HP Hewlett Packard LTO 4 SCSI User Manual

HP LTO Ultrium tape drives  
technical reference manual  
LTO 4 FC, SCSI and SAS drives  
volume 2: software integration  
Edition 1, June 2007  
HP restricted  
Installation and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8  
Information in Cartridge Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12  
LTO cartridge memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
Identifying tape cartridge types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
Tape status and capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Finding the remaining capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Interpreting Log Sense data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Using the SET CAPACITY command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
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Allow overwrite of last filemarks before the EOD data set . . . . . . . . . . . . . . . . . . . . . . . . 23  
Using Cartridge Memory instead of tape headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  
Treatment of reserved fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43  
Recommended power-up sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43  
Recommended load-unload configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44  
Recommended Get Drive Status polling frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
ACI protocol communications retry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
Upgrading the drive firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
Handling irregular cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46  
Frequently asked questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49  
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Controlling data compression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51  
3h—MEDIUM ERROR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62  
TapeAlert polling usage model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88  
One-Button Disaster Recovery (OBDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
Supporting OBDR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
Responding to the ‘Clean’ LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
Requirements for drivers and logical device managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91  
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93  
HP LTO Ultrium 4 drives technical reference manual, volume 2: software integration  
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Related documents  
This is one of six volumes that document HP Ultrium drives. This volume provides background  
information for driver and application developers. The following products are covered:  
HP LTO Ultrium 4 full-height SCSI tape drives  
HP LTO Ultrium 4 full-height SAS tape drives  
HP LTO Ultrium 4 full-height Fibre Channel tape drives  
NOTE: Throughout this manual frequent reference is made to SCSI commands. For more  
information on SCSI commands for HP Ultrium drives see volume 3, The SCSI Interface or The SAS  
Interface, of the HP LTO Ultrium Technical Reference Manual set. Ordering details are given below.  
Documents specific to HP Ultrium drives  
Hardware Integration Guide, volume 1 of the HP LTO Ultrium Technical Reference Manual  
Host Interface Guide, volume 3 of the HP LTO Ultrium Technical Reference Manual  
Specifications, volume 4 of the HP LTO Ultrium Technical Reference Manual  
UNIX, Linux and OpenVMS Configuration Guide, volume 5 of the HP LTO Ultrium Technical  
Reference Manual  
Please contact your HP supplier for copies.  
The features and benefits of HP Ultrium drives are discussed in the HP Ultrium Technology White  
Paper.  
For a general background to LTO technology and licensing, go to  
Documentation map  
The following will help you locate information in the Technical Reference Manual. A reference like  
1 HW Integration: ch. 7” means Volume 1, Hardware Integration Guide, of the HP LTO Ultrium  
Technical Reference Manual, chapter 7.  
Drives—general  
FC Drives  
SCSI Drives  
1 HW Integration: ch. 7  
1 HW Integration: ch. 6  
4 Specifications  
SAS Drives  
1 HW Integration: ch. 4  
1 HW Integration: ch. 3  
Connectors  
Front panel LEDs  
Specifications  
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Installation and configuration  
FC Drives  
SCSI Drives  
1 HW Integration: ch. 7  
2 SW Integration: ch. 2  
1 HW Integration: ch. 5  
SAS Drives  
1 HW Integration: ch. 4  
Connectors  
Determining the configuration  
External drives  
n/a  
1 HW Integration: ch. 1  
In libraries  
n/a  
n/a  
1 HW Integration: ch. 4  
In servers  
1 HW Integration: ch. 3  
n/a  
n/a  
n/a  
In tape arrays  
5 UNIX, Linux, OpenVMS Configuration  
1 HW Integration: ch. 8  
Linux configuration  
Modes of usage  
OpenVMS configuration  
Optimizing performance  
n/a  
n/a  
5 UNIX, Linux, OpenVMS Configuration  
1 HW Integration: ch. 8  
2 SW Integration: ch. 4  
5 UNIX, Linux, OpenVMS Configuration  
UNIX configuration  
Operation  
FC Drives  
SCSI Drives  
SAS Drives  
n/a  
1 HW Integration: ch. 5  
External drives  
In libraries  
1 HW Integration: ch. 1  
n/a  
n/a  
1 HW Integration: ch. 4  
In servers  
1 HW Integration: ch. 3  
n/a  
In tape arrays  
Cartridges  
FC Drives  
SCSI Drives  
SAS Drives  
2 SW Integration: ch. 5  
Cartridge Memory (LTO-CM)  
Cartridges  
1 HW Integration: ch. 5  
1 HW Integration: ch. 9  
2 SW Integration: ch. 1  
Managing the use of cartridges  
Use of cartridges  
2 SW Integration: ch. 3  
Interface  
FC Drives  
SCSI Drives  
3 Host Interface  
SAS Drives  
FC, SCSI and SAS host interface guide  
Commands  
3 Host Interface: ch. 5  
1 HW Integration: ch. 6  
1 HW Integration: ch. 10  
Error codes  
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FC Drives  
SCSI Drives  
SAS Drives  
3 Host Interface: ch. 1  
2 SW Integration: ch. 3  
3 Host Interface: ch. 2  
3 Host Interface: ch. 5  
Implementation  
Interpreting sense data  
Messages  
Mode pages  
—see the MODE SENSE command  
3 Host Interface: ch. 4  
2 SW Integration: ch. 6  
3 Host Interface: ch. 5  
Pre-execution checks  
Responding to sense keys and ASC/Q  
Sense keys and ASC/Q  
—see REQUEST SENSE command  
n/a  
3 Host Interface: ch. 3  
Task management functions  
Maintenance and troubleshooting  
FC Drives  
SCSI Drives  
SAS Drives  
2 SW Integration: ch. 5  
2 SW Integration: ch. 7  
Cleaning  
n/a  
1 HW Integration: ch. 5  
External drives  
1 HW Integration: ch. 1  
In libraries  
n/a  
n/a  
1 HW Integration: ch. 4  
In servers  
1 HW Integration: ch. 3  
2 SW Integration: ch. 7  
2 SW Integration: ch. 1  
n/a  
In tape arrays)  
Monitoring drive and tape condition  
Software troubleshooting techniques  
Dealing with errors  
FC Drives  
SCSI Drives  
SAS Drives  
1 HW Integration: ch. 6  
1 HW Integration: ch. 10  
Error codes  
2 SW Integration: ch. 5  
3 Host Interface: ch. 4  
2 SW Integration: ch. 7  
2 SW Integration: ch. 3  
2 SW Integration: ch. 3  
Handling errors  
Logs—see the LOG SENSE command  
Recovering from write and read errors  
Software response to error correction  
Software response to logs  
TapeAlert log  
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LTO Ultrium features  
FC Drives  
SCSI Drives  
SAS Drives  
1 HW Integration: ch. 2  
1 HW Integration: ch. 2  
Autoload  
Automation Control Interface (ACI)  
Cartridge Memory (LTO-CM)  
1 HW Integration: ch. 2  
2 SW Integration: ch. 5  
2 SW Integration: ch. 5  
Data compression, managing  
OBDR and CD-ROM emulation  
Performance optimization  
2 SW Integration: ch. 7  
n/a  
1 HW Integration: ch. 8  
2 SW Integration: ch. 1  
2 SW Integration: ch. 4  
2 SW Integration: ch. 1  
2 SW Integration: ch. 5  
Performance, factors affecting  
Software design  
Supporting LTO Ultrium features  
General documents and standardization  
See http://www.t10.org/t10_main.htm for INCITS SCSI Primary Commands—3 (SPC-3), SCSI  
Streaming Commands (SSC-3) and other specifications  
Copies of documents of other standards bodies can be obtained from:  
INCITS  
11 West 42nd Street  
New York,  
NY 10036-8002  
USA  
ISO  
CP 56  
CH-1211 Geneva 20  
Switzerland  
ECMA  
114 Rue du Rhône  
CH-1204 Geneva  
Switzerland  
Tel: +41 22 849 6000  
Global Engineering  
Documents  
2805 McGaw  
Irvine, CA 92714  
USA  
Tel: 800 854 7179 or 714 261 1455  
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1 Designing backup applications  
In today’s computer market, software applications that use tape drives to copy the information from  
a computer’s hard disk for safe keeping are readily available for many different operating systems.  
Unfortunately, not all these applications take advantage of the advances made in tape technology  
over the past few years. This section examines some of the characteristics that a good backup utility  
should include.  
Optimizing performance  
There are some fundamental things that tape management applications should implement when  
dealing with Ultrium drives:  
Use large data transfer sizes.  
Control and monitor data compression.  
Ensure directory information is safe and accurate.  
Maximize the use of the tape drive’s internal buffering capability.  
Each of these is discussed below.  
For more information on optimizing performance, see “Factors affecting performance” on page 27.  
Large data transfer size  
Applications should use large data transfer sizes to make better use of the Ultrium drive’s internal  
buffers. A good goal to set is at least 128 KB each for read or write operation, with an ideal target  
of 256 KB:  
For fixed-length block mode reads and writes, provided the block size multiplied by the number  
of blocks to be transferred is at least 128 KB, drives will provide peak performance. Small block  
sizes (512 bytes) are acceptable so long as they are written and read in fixed-length block  
mode using large transfers.  
For variable-length block mode reads and writes, the transfer length should be at least 256 KB.  
Data compression control  
Ultrium drives have built-in hardware data compression. Backup applications should incorporate  
features to report the actual compression ratio achieved during backup operations.  
The typical compression ratio achieved during backup operations on PC and UNIX networks is 2:1,  
but this can vary widely depending on the actual data being compressed.  
For more information, see “Controlling data compression” on page 51.  
Non-immediate commands  
Performance can be improved by only using immediate mode WRITE FILEMARKS commands.  
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NOTE: Using immediate mode with other commands does not improve performance and can  
cause problems when writing a driver. The SCSI specification requires that if a command is issued  
with the IMMEDIATE bit set to 0, the drive must flush its data buffer before it carries out the  
operation. This takes time.  
Managing the use of tapes  
The Ultrium format enables applications to monitor the performance of tapes closely, to indicate  
when tape heads need cleaning, and when a tape should be discarded.  
See “Use of tapes” on page 19 for more information.  
Information in Cartridge Memory  
The LTO Cartridge Memory holds a number of pages of information that contain data about the  
tape’s history, such as the amount of data written to and read from the tape, the number of times a  
cartridge has been loaded and the tape threaded into a drive, and the number of read or write  
against backing up onto a tape of dubious quality, or one that is reaching the end of its life.  
Cleaning tape heads  
The ‘Clean’ LED on the front of HP Ultrium drives indicates when a cleaning cartridge should be  
used. There are two ways for backup applications to determine when the tape heads need cleaning  
and to prompt the user to clean the drive:  
Use TapeAlert—see “Monitoring the condition of the drive and media” on page 78 for details.  
Send a SCSI REQUEST SENSE command to look at the CLN bit in the sense data. If the bit is set,  
the drive needs cleaning.  
In an automation context, the tape drive tells the automation controller that a cleaning tape needs to  
be used through two bits in the ACI Get Drive Status command.  
The Cleaning Needed bit signals deterioration in the write or read margin of the drive and  
indicates that a cleaning cartridge should be used as soon as possible. Once the drive has been  
cleaned successfully, the Cleaning Needed bit will be cleared.  
The Cleaning Required bit indicates that the drive is unable to read or write unless the drive is  
first cleaned, so a cleaning cartridge should be used immediately. Following a successful clean,  
the Cleaning Required bit will be cleared.  
Monitoring tape use  
Drives can report the actual amount of data that has been written to the tape, and the amount of  
available space on the tape. From this information, applications for Ultrium drives can be designed  
to calculate the percentage of tape used, and give the user feedback on the actual progress of the  
backup operation. This is a significant improvement over other technologies, such as DC6000 QIC  
products, that require the application to estimate what is going on.  
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See “Tape Capacity Log Page” under the LOG SENSE command in Chapter 3 of The SCSI Interface,  
Volume 3 of the HP LTO Ultrium Technical Reference Manual for more information.  
While the reliability of tape products and applications is getting better all the time, problems do still  
occur. There are some very simple techniques that could be incorporated by application developers  
to simplify the process that a user must go through to resolve problems.  
For additional information, see “Exception handling” on page 77.  
TapeAlert  
The TapeAlert facility in HP Ultrium drives allows applications to help avoid trouble by prompting  
the user to take remedial action, or in some cases, through the application automatically performing  
remedial actions itself.  
For example, if the drive is experiencing trouble writing, the software can prompt the user to clean  
the heads, or, if there are several drives or an autoloader, automatically clean the heads without  
involving the user.  
See “Monitoring the condition of the drive and media” on page 78 for more details.  
Diagnostic logs  
SCSI tape drives report problems in response to a REQUEST SENSE command from the host. If the  
backup application stores this information in a log file, it becomes significantly easier to  
troubleshoot problems, because the data can be used to pinpoint what is wrong.  
Displaying drive information  
Troubleshooting can also be simplified by giving users the ability to look at the drive’s firmware  
revision, and information about the host bus adapter. This information can be found by executing an  
INQUIRY command, and can then be displayed, or stored in a log file.  
Drive tests  
A basic read/write test should be included in a backup application to check the integrity of the  
hardware. This should also allow the user to scan the SCSI bus and to solve problems concerning  
the device setup and configuration.  
Design goals for LTO backup applications  
Use large SCSI read/write transfer sizes (256 KB is recommended).  
Incorporate data compression control and report the compression ratios achieved.  
Consider where to store directory information depending on the nature of the application.  
Only use immediate WRITE FILEMARK commands, but avoid using other commands in immediate  
mode.  
Use Cartridge Memory information to measure tape quality before backing up starts.  
Use the TapeAlert log to prompt the user to take remedial action to avoid problems.  
Use “cleaning required” indicators in the software to either prompt the user or enable the library  
to use a cleaning cartridge to clean the drive heads.  
Allow users to set custom cleaning schedules.  
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Use log files to store Inquiry and Sense Key/Error Code information about error conditions.  
Allow users to access drive firmware revision and HBA characteristic information  
Include the capability to download firmware.  
Incorporate simple diagnostic capabilities, such as Write/Read tests and SCSI device discovery.  
Incorporate online help.  
14 Designing backup applications  
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2 Configuration and initialization  
This section covers the following topics:  
Operating System drivers  
Inquiry string recovery, finding information about the drive through the INQUIRY command  
Additional LUN support, for operation with an autochanger device  
Fibre Channel support  
Operating system drivers  
Windows  
HP have a proprietary driver for Windows 2000 and Windows 2003. It is  
intended that the driver is freely licensed to any software partner that requires it.  
For the latest driver support for HP tape drives, please visit the following HP web  
NetWare  
UNIX  
HP has worked with Novell to provide driver support for HP’s Ultrium products.  
See the UNIX, Linux and OpenVMS Configuration Guide for details of how to  
implement Ultrium support under the popular UNIX flavors.  
Inquiry string recovery  
HP Ultrium devices should not be recognized solely by the contents of their SCSI INQUIRY strings. In  
the past, hard-coded recognition of Inquiry strings has meant that software support for follow-on  
products from HP has been delayed when, to all intents and purposes, the new product was  
practically identical to the previous generation. For Ultrium, it is recommended that software  
applications ‘key off’ only the first eight bytes of the Product ID field—the text “Ultrium . The  
only use for the remainder of the bytes in this field is that they will be visible on-screen during the  
boot process of PC systems. As with HP’s DDS products, there will be very little difference between  
the first Ultrium drives and succeeding generations in terms of their basic SCSI characteristics; they  
will just store more data faster.  
Standard INQUIRY Page Data  
Vendor ID (bytes 8–15)  
Product ID (bytes 16–23)  
Product ID (bytes 24–31)  
Product Revision Level (bytes 32–35)  
SCSI  
“HP  
“Ultrium ”  
“4-SCSI ” “4-SCSI ” “4-SCSI ”  
CRMV CRMV CRMV  
SAS  
“HP  
“Ultrium ”  
FC  
“HP  
“Ultrium ”  
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Product ID, first 8 bytes  
“Ultrium ”  
This will be the same for all HP Ultrium products, regardless of generation or model.  
Product ID, last 8 bytes  
1st byte:  
Generation identifier:  
“4” LTO 4 (1600 GB at 2:1 compression)  
2nd byte  
” Hyphen separator (ASCII 2Dh)  
3rd–6th bytes “SCSI” SCSI protocol, regardless of transport or interface type  
Product Revision Level  
1st byte  
Product codename ID:  
“A”  
“B”  
“H”  
LTO 4 SAS full-height drive  
LTO 4 SCSI full-height drive  
LTO 4 FC full-height drive  
2nd byte  
Release type:  
“0, 1”  
“2”  
“3, ...  
Development  
Formal release  
Post-release  
3rd byte  
4th byte  
Minor release level: “0”–“9, then A” ”Z”  
Firmware variant:  
“D”  
“W”  
Standard distribution firmware  
Standard HP automation firmware  
Example  
If new drive families or variants support features that are not available in previous generation  
products, you can detect the existence of these features through the SCSI MODE SENSE and LOG  
SENSE commands. Exact details will become available as new products are defined. There is no  
need to limit driver or application connectivity to a single HP Ultrium product type.  
To determine the drive technology family:  
Examine only the first eight bytes of the Product ID field (the text “Ultrium ”).  
To determine the Ultrium format generation:  
Use one of the following two methods, of which the second is preferred:  
Examine the character in byte 9. A 4” indicates format LTO 4 (1600 GB capacity at 2:1  
compression) and so on.  
Preferred method: Use the SCSI REPORT DENSITY SUPPORT command.  
For an LTO 4 product with LTO Ultrium 4 media, the following will be returned:  
Primary Density Code:  
46h  
Assigning Organization: LTO-CVE Linear Tape Open Compliance and Verification Entity  
Density Name:  
U-416 16 track  
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Since LTO 4 drives cannot write to Ultrium-2 media, the WRTOK bit will be clear for this media  
type.  
Support for additional LUN  
Enabling additional LUN support  
When enabled by an internally-connected autochanger device, an extra Logical Unit Number (LUN)  
will be available at the target’s SCSI ID. This allows the attached autochanger device to be  
addressed via the tape drive. See ”Automation interface” on page 35. For ADI Bridging usage, the  
automation LUN will usually be LUN1.  
No other LUNs are available on the drive, although HP is looking to provide new functionality  
through the use of additional LUNs in future products.  
Supporting additional LUNs  
When working with a library vendor who is incorporating HP Ultrium drives in products, software  
developers should liaise directly with the vendor about the functionality of the hardware available  
through the ADI or ACI.  
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18 Configuration and initialization  
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3 Use of tapes  
HP Ultrium user documentation and “Cartridges, Chapter 9 of the Hardware Integration Guide,  
Volume 1 of the HP LTO Ultrium Technical Reference Manual, also contain information on  
cartridges.  
Timing considerations are discussed in “Time-out values” on page 28.  
LTO cartridge memory  
NOTE: “Cartridge Memory” is the Ultrium version of the more general term “Media Auxiliary  
Memory” or MAM, covering all media types.  
Cartridge Memory has been added to the LTO cartridge for the following reasons:  
It speeds up load and unload times by removing the need to read system areas.  
It speeds up movement around tape by storing the tape directory (physical to logical mapping).  
It increases tape reliability because fewer tape passes are needed.  
It stores diagnostic and log information for tracking purposes.  
Most of these uses are invisible to applications and handled internally by the drive. There is  
potential for applications to use the Application Specific Data” area. This is being investigated.  
For more details, see “Using Cartridge Memory” in “Using Special Features in Libraries, Chapter 2  
of the Hardware Integration Guide, Volume 1 of the HP LTO Ultrium Technical Reference Manual.  
Identifying tape cartridge types  
Using Cartridge Memory attributes  
To identify the type of cartridge in the drive, read the Medium Type attribute in Cartridge Memory:  
Attribute ID 0408h 00h Read/write (normal) data cartridge  
01h Cleaning cartridge  
80h WORM cartridge  
Using MODE SENSE  
Examine the Medium Type field in the Mode Parameter header of the MODE SENSE command (byte  
1 in the 6-byte version, byte 2 in the 10-byte version):  
Medium Type  
01h WORM cartridge  
80h SCSI and SAS only: CD (the drive is in CD-ROM mode)  
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Tape status and capacity  
Following autoload or a LOAD command, the software can determine the state of the tape and its  
capacity from the Cartridge Memory and the Tape Capacity Log pages retrieved through the LOG  
SENSE command. The information can also be invoked as a console operation at any time to find  
the status and condition of the media.  
Tape capacity figures can be used for two purposes:  
To give an application or user an indication of whether the tape has enough capacity for a  
proposed backup. When using data compression, however, this is of little value, since the  
compression factor cannot be predicted accurately.  
Periodically during a backup to give an approximation of the amount of tape left.  
CAUTION: An application should not use the capacity reported in the Tape Capacity log to fix the  
backup size. This will result in permanent capacity truncation that could represent a significant  
percentage of the available capacity.  
Finding the remaining capacity  
Examine the Tape Capacity Log to estimate the effective remaining capacity of the tape  
(data-compression factors are not considered).  
Interpreting Log Sense data  
The following points affect the values returned in the data:  
Units  
Capacities are given in megabytes (1,048,576 bytes) of user data and assume no  
compression.  
General  
If data compression is used, the capacities are specified as though the drive is in  
pass-through mode. The data compression factor is not considered.  
Regions of tape used by the system, such as EOD areas, are not included in  
capacities specified. In other words, values are conservative.  
An allowance for read-after-write retries is made.  
Maximum Maximum capacity values are only valid when the tape has completed a load  
Capacity  
sequence. If an immediate mode LOAD is made, LOAD SENSE will not return valid  
information until the tape has been successfully loaded and tape motion has ceased.  
Remaining The remaining capacity value is the amount of tape remaining calculated from EOD.  
Capacity  
Remaining capacity values are only valid after the successful completion of the  
following commands in non-immediate mode:  
LOAD  
LOCATE  
VERIFY  
MODE SELECT  
WRITE  
READ  
REWIND  
SPACE  
WRITE FILEMARKS  
The values after any subsequent command cannot be relied on unless the command  
is a sense type that does not cause any tape motion.  
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Capacity calculations are based on estimates; reported values can be subject to error in two ways:  
Random errors caused by tolerances in tape length, hub diameter, and so on.  
Systematic errors caused by ignoring system areas, and so on. They ensure the calculated  
capacity is actually available to the user. It is usually possible to write considerably more data  
than the calculated capacity.  
Using the SET CAPACITY command  
You can modify the capacity of a tape by changing the logical length of the tape through the SET  
CAPACITY command. The primary use envisaged is for testing purposes, although it may also be  
used in other circumstances where a shortened tape may be beneficial.  
NOTE: All data currently on the tape will be lost following successful execution of this command.  
The command is only accepted when the media is positioned at Beginning of Media (BOM).  
With WORM cartridges, the command is only accepted and executed if the cartridge has not been  
initialized, that is, it has never been written to. Otherwise the cartridge is rejected with CHECK  
CONDITION, sense key of Data Protect and additional sense of 300Ch (WORM media—overwrite  
attempted). TapeAlert flags 3Ch (WORM media—overwrite attempted) and 09h (write-protect) are  
set.  
Command descriptor block  
7
6
5
4
3
2
1
0
0
1
2
3
4
5
Operation Code (0Bh)  
Reserved (0)  
Immed  
Reserved (0)  
(MSB)  
Capacity Proportion Value  
Control  
(LSB)  
CDB fields  
Immed  
0 Status will not be returned until the SET CAPACITY operation has completed.  
1 Status will be returned as soon as the CDB has been parsed.  
Capacity  
The portion of the total volume capacity to be made available for use. The value  
Proportion Value is the numerator of a fraction with a denominator of 65,535. The resulting  
-------------------------------------------------------------------------------------------------------------------------------  
available capacity will be  
.
65535  
Note that the LTO-4 format enforces a minimum tape length. A value that would result in a tape  
length below this minimum will be silently rounded up to the minimum permitted length.  
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The following table gives the minimum acceptable Capacity Proportion Values and the approximate  
capacity they will give:  
Cartridge Min. capacity proportion value  
Resultant approx. min. capacity  
Max. capacity  
200 GB  
Ultrium 2  
Ultrium 3  
Ultrium 4  
1605h  
151Ah  
1055h  
17.2 GB  
33 GB  
51 GB  
400 GB  
800 GB  
NOTE: Capacities are approximate and can be affected by defects that reduce the actual capacity  
of the tape. Other factors, such as compression and block packing, may also affect capacity.  
WORM media  
HP Ultrium-3 WORM (Write Once—Read Many) data cartridges are two-tone grey/yellow to  
distinguish them from RW media. They have a unique Cartridge Type stored in the Cartridge  
Memory, so that they will be rejected by non-WORM compatible drives. For automation  
configurations with auto-eject disabled, the cartridge will not be physically ejected from the drive  
but held at the “ready eject” position.  
The write-protection tab behaves as on Read/Write (RW) cartridges.  
How WORM media works  
Drives use the EOPD (End of Protected Data) value to control the use of WORM tapes.  
EOPD is a logical position on tape that is automatically calculated based on the End of Data (EOD)  
value read from the Cartridge Memory (CM) when the cartridge is loaded into the drive. The EOD  
value is an “intrinsic” code stored and protected in the Cartridge Memory of each WORM  
cartridge, and updated after each write session. The EOPD indicates that data between BOM and  
this position cannot be overwritten.  
The EOPD value is held within the drive’s memory. It is updated automatically and continuously as  
each block of data (typically 64 or 128 KB) is written to tape, so the EOPD value indicates a logical  
position immediately after the last block of data written to tape.  
When the cartridge is unloaded, the drive updates the EOD value in CM to reflect the end of  
successfully written data on the cartridge, and clears the EOPD value stored within the drive. Any  
future writes to the cartridge will occur after the location of the EOD, which will become the initial  
location for EOPD during the next write operation.  
Changes to SCSI commands  
New additional sense codes and TapeAlert flags  
ASC/Qs:  
300Ch (WORM medium—overwrite attempted)  
300Dh (WORM Medium—integrity check failed)  
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TapeAlert flags:  
3Bh (WORM medium—integrity check failed)  
3Ch (WORM medium—overwrite attempted)  
Error Usage page  
For WORM cartridges, the Wrap Number fields in the Error Usage page are replaced by an Error  
Code field. This contains the ASC/Q value reported to the host when the associated error was  
detected.  
Only appended writes accepted  
If a WORM cartridge is placed in a WORM-compatible drive, the drive will accept write commands  
(records, filemarks) only if the current logical position is beyond the position identified by the EOPD  
value. If a write command is received by the drive when the logical position is before the EOPD  
value, the command will be rejected and CHECK CONDITION returned with sense key of Data  
Protect and additional sense of 300Ch (WORM medium—overwrite attempted). The TapeAlert  
flags 3Ch (WORM medium—overwrite attempted) and 09h (write-protect) are set.  
ERASE commands rejected  
ERASE commands (short or long) to a drive containing a WORM cartridge will not overwrite or  
erase user data on tape. Any ERASE command that would result in user data being over-written on  
tape is rejected and CHECK CONDITION returned with sense key of Data Protect and additional  
sense of 300Ch (WORM medium - overwrite attempted). The TapeAlert flags 3Ch (WORM  
medium—overwrite attempted) and 09h (write-protect) are set.  
SET CAPACITY command  
The SET CAPACITY command will only be accepted and executed if the WORM cartridge has not  
been initialized, that is, it has never been written to.  
If a SET CAPACITY command is received by the drive when the cartridge has been initialized, it is  
rejected and CHECK CONDITION returned with sense key of Data Protect and additional sense of  
300Ch (WORM medium—overwrite attempted). The TapeAlert flags 3Ch (WORM  
medium—overwrite attempted) and 09h (write-protect) are set.  
Re-writing media labels  
If there is no user data on the tape, the media label can be rewritten. The label contains software  
application-related information such as a unique identification code and does not contain user  
data.  
Writing is allowed when the current logical position is at BOT and:  
there are only filemarks between this position and EOD, or  
records, between this position and EOD.  
Allow overwrite of last filemarks before the EOD data set  
At the end of a backup or archive session, many software applications write two filemarks to tape  
immediately before the EOD data set is written. These filemarks are logical markers that enable the  
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application to locate the tape in preparation for subsequent writing or reading operations. At the  
start of an appending archive or backup session, it is common for the application to locate the tape  
to a logical position immediately preceding the second filemark and to overwrite the second  
filemark during the data appending session.  
Writes are allowed:  
when the current logical position is at EOD. This means that the drive must have read the EOD  
from tape before attempting to overwrite it.  
when there are only filemarks between the current logical position and EOD, and at least one  
filemark immediately before the current logical position.  
Using CM to check tape integrity  
Drives that support WORM cartridges check that the anti-tampering measures have not been  
violated before and during media access operations. If a violation is detected, for example, if the  
content of the CM does not match the content of the tape, the cartridge is treated as read-only, and  
Tape Alert flag 3Bh (WORM medium—integrity check failed) is set.  
HP strongly recommends that software applications check for the presence of TapeAlert flag 3Bh  
after a tape load and periodically during operation. If the flag is set, the software should alert the  
operator and log the incident for audit.  
Hosts can use the WTRE bit on the Device Configuration mode page (bit 6, byte 15 of mode page  
10h) to control the behavior of the drive when reading WORM media whose WORM integrity is in  
doubt and which may have been tampered with. See details of the mode page in Chapter 4 in SCSI  
Interface, volume 4 of the HP LTO Ultrium Technical Reference Manual for more information.  
Behavior with a missing or inconsistent EOD value  
A missing EOD value or one in which the value on tape differs from that in CM can be caused by:  
CM corruption  
deliberate, malicious alteration of the EOD value in the CM  
an interruption of the drive power supply while writing data.  
If the CM indicates that the EOD is not valid (for example, if the drive has powered down during a  
write), TapeAlert flag 04h (Media) will be set on cartridge load.  
The drive behaves as for a RW cartridge with no EOD data set, except that any attempt to overwrite  
data will be rejected with CHECK CONDITION, a sense key of Data Protect and additional sense of  
2700h (write-protected). Tape Alert flag 09h (Write-Protect) is set.  
Unique media identifier  
For added security, HP strongly recommends that applications read and track cartridge  
manufacturer and serial number values from the Cartridge Memory using MAM access commands:  
Attribute ID 0x0400: Cartridge manufacturer ID  
Attribute ID 0x0401: Cartridge serial number  
Both values should be read and concatenated to ensure that the number is unique.  
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Barcode support  
Ultrium barcode support is required for WORM media so that the application and tape library can  
distinguish WORM media from normal RW media or cleaning cartridges.  
HP recommends the use of the following barcode formats for Ultrium media:  
123456L2 LTO Ultrium 2  
123456L3 LTO Ultrium 3  
123456L4 LTO Ultrium 4  
:
:
123456LT LTO Ultrium 3 – WORM  
:
:
Responding to Cartridge Memory data  
NOTE: Software should use the TapeAlert log in preference to the Cartridge Memory to detect  
conditions which require the user or host to take preventative action. See “Monitoring the condition  
of the drive and media” on page 78.  
These guidelines indicate how host applications should make use of the data contained in the  
Cartridge Memory during normal operation (that is, when tapes are not permanently  
write-protected, not constantly re-formatted).  
The console messages triggered by these criteria should clearly indicate a course of action to the  
end-user, such as the following:  
1. Clean the tape heads using a cleaning cartridge.  
2. Insert a new tape cartridge.  
3. Archive the data.  
Load count  
NOTE: This only applies when non-write-protected cartridges are used.  
The load count is the number of times the cartridge has been loaded into a drive and accessed.  
of the tape. This conservative estimate is also influenced by the quality of the application and the  
driver software in being able to maintain streaming, thereby preventing repositioning over the same  
area of tape, without data being transferred.  
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RWW retry counts  
Data is read immediately after being written to tape to establish that it has been written correctly.  
Increases in RWW retries can be due to four factors:  
Deterioration in the media  
Dirty heads  
Drive malfunction  
The operating environment  
Corrective action  
The recommended criteria for corrective action are as follows:  
RWW Retries > 5% Total data sets written  
When using tapes without write-protection, use the Total count.  
The corrective action should be as follows:  
1. Use another tape and, for a write operation, try repeating the write. For a read operation, try  
reading data from the tape.  
2. See whether the current RWW value is within the recommended limit.  
3. If the values are now within the limit, you can assume that the original tape is nearing the end of  
its useful life. Proceed as follows:  
• For a write operation, discard the tape and use a new one.  
• For a read operation, transfer the data to a new tape.  
4. If the value is still outside the limit, clean the tape heads with a cleaning cartridge and try  
repeating the operation with the original tape.  
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4 Factors affecting performance  
This chapter contains techniques and information to help you design software applications so that  
they use the tape drive’s potential as efficiently as possible.  
Ways of optimizing performance:  
• Ensuring the recommended minimum transfer sizes page 27  
• Identifying the media type page 28  
• Using Cartridge Memory instead of tape headers page 28  
• Using the Performance Log page to diagnose problems page 28  
Time-out values to help you tune timings in backup applications page 28  
Log pages—recommended support page 29  
Factors affecting performance, relating separately to the host, drive and format page 29  
Ways of optimizing performance  
HP’s Ultrium drives are high-performance products. Application software may require significant  
enhancement in order to capitalize on this speed. There are a number of areas to look at and these  
are discussed below.  
Further details can also be found in the “How to optimize the performance of hp ultrium tape drives”  
white paper.  
Detecting the drive’s speed  
Applications should not key off Inquiry strings in order to tell the difference between different speed  
drives. It is better to use the Performance Log page see under the LOG SENSE command in Chapter  
4, “Commands, of SCSI Interface, Volume 3 of the HP LTO Ultrium Technical Reference Manual.  
In the Performance Log page (34h), parameter 04h (Native data rate) gives the native data rate of  
the drive in units of 100 KB/s. LTO 4 drives give the value 04B0h, indicating 120 MB/s with  
Ultrium 4 media or no cartridge loaded. If a previous generation cartridge is loaded, the value will  
be lower.  
Ensuring the recommended minimum transfer sizes  
Use the Data Compression Log page. HP cannot diagnose performance issues without accurate  
reporting of the current compression or the average compressibility over a backup session. Make  
sure that you report the log page.  
(OBDR)” on page 89), it is important to note that in some situations the SCSI block size may have to  
be fixed for a given tape for format reasons. This means that if the host writes 2 KB blocks to support  
OBDR, it may have to continue to write 2 KB blocks for the rest of the tape; it depends on the format  
compatibility required by the overall system. However as HP Ultrium drives are insensitive to  
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absolute block size, performance should not suffer, but do ensure that the transfer size is at least  
256 KB.  
Maximum block size  
The READ BLOCK LIMITS command indicates that block sizes and variable length transfer sizes are  
supported for values between 1 byte and 16,777,215 bytes.  
Media type identification  
HP recommends that you use the REPORT DENSITY SUPPORT command (with the Media bit enabled)  
to identify the type of media loaded in the drive.  
Using Cartridge Memory instead of tape headers  
For optimum performance, it is also important that the host writes application tape header  
information to the Cartridge Memory (see “Cartridge Memory (LTO-CM)” on page 35) rather than  
to the actual tape. This allows cartridges to load and unload quickly and prevents excessive media  
wear at the beginning of the tape. As the access method to Cartridge Memory data is an open  
standard, it also permits other software systems to identify alien media positively in shared storage  
environments.  
Using the Performance Log page for diagnosing problems  
The Performance Log page (34h) contains data that should allow application software to monitor  
the data-rate being sent to the drive dynamically. For details, see the LOG SENSE command in  
Volume 3, SCSI Interface, of the HP LTO Ultrium Technical Reference Manual.  
Time-out values  
SCSI Command  
Load  
Unload  
Rewind (full tape length)  
Space/Locate/CD-ROM Read (10)  
Erase (long)  
Recommended Time-Out Value  
10 minutes  
10 minutes  
10 minutes  
20 minutes  
5 hours  
Erase (short)  
5 minutes  
Write/Write Filemarks  
5 minutes  
Read  
20 minutes  
1 minute  
1 minute  
Read/Write Attribute (MAM), with 1 KB of attribute data  
Non-tape movement (such as TEST UNIT READY, INQUIRY)  
Notes:  
These values are for a single SCSI command in non-Immediate mode. As most commands will  
be sent in Immediate mode, status will be received by the host typically within 20 ms. In such  
cases, the time-out given indicates when the drive will have completed the operation and be  
ready for the next tape movement command.  
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All of these values may be subject to change.  
There is no retension facility.  
Recommended support of log pages  
Some of the media-related data items on the log pages are duplicates of data that is available  
through the READ ATTRIBUTES command using the Media Auxiliary Memory (MAM) access  
specification. We recommend that you use MAM commands as the primary source for such data,  
because this access method is portable to tape drives from other vendors, that is, the data is not in  
a vendor-unique format.  
In the long term, HP intends to expose all tape usage and drive hardware usage information via the  
industry-standard MAM-format commands, so it is wise to start to implement this approach now.  
For full details of the Ultrium log pages, see the LOG SENSE command in Chapter 4, “Commands,  
of SCSI Interface, Volume 3 of the HP LTO Ultrium Technical Reference Manual.  
Factors affecting performance  
Further details on improving performance can be found in the “How to optimize the performance of  
hp ultrium tape drives” white paper.  
Host-related factors  
Performance Factor  
Detail  
Host SCSI performance  
The execution of each SCSI command involves a number of bus  
phases, of which the data phase is only one.  
The key phases are as follows:  
Intra-command bus-free time  
Arbitration and selection  
Message out  
Command  
Host Burst Rate  
During the data phase of each SCSI command, data is transferred to  
or from the drive at the host’s burst rate. If the host’s burst rate is slow,  
then it takes longer to transfer the data. Extra time during this phase is  
simply added to the total command time, and so it can affect the  
overall performance.  
Even if the burst rate is much faster than that required to maintain  
streaming, the total command time may prevent the commands from  
being issued fast enough.  
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Performance Factor  
Detail  
Example: SCSI: Consider an 8 KB transfer at burst rates of 8 MB/s and 1 MB/s.  
The fast transfer takes 1 ms, while the slow transfer takes 8 ms. Since  
the rest of the command may only take 4–5 ms, the difference of 7 ms  
is very significant.  
SAS and FC: The SAS link is capable of 3 Gb/s (300 MB/s) whereas  
the performance of the FC drive depends on the negotiated link speed  
of the host/HBA port, any intermediate switch ports and the drive port.  
The ports will negotiate to the highest possible mutually supported  
speed, ideally 4 Gb/s (400MB/s), then 2 Gb/s (200MB/s) or as low  
as 1 Gb/s (100MB/s).  
Disk Subsystem  
Performance  
The speed and configuration of the disks used will have a significant  
impact on the backup speed of the whole system.  
Recommendation: Using RAID can have a significant effect on the throughput of the  
whole system, by the use of interleaved disk reads. Use more spindles  
where possible or a reasonably sized RAID system. More disks means  
more throughput.  
Note that the Raid level makes a difference to performance. RAID5 will  
be slower for writes (restores) than reads (backups). RAID0 and RAID1  
are faster but expensive in terms of numbers of spindles required and  
not so tolerant to disk failure (RAID0 is particularly intolerant).  
File System Efficiency  
Operating systems vary in the efficiency with which they retrieve files  
sequentially for backup applications. Most operating system  
development effort is put into speeding up access times within files  
rather than file seek times.  
Consider using staging technology to stage an image before writing to  
tape, particularly with many small files, which will impact performance  
due to file accession.  
Hardware Configuration If the disk and tape drives are on separate buses, the effective  
available bandwidth can be doubled.  
Recommendation: Use one HBA for disks, and put the tape drive on a separate bus. It  
makes sense to split heavily used FC cards across separate PCI busses  
so that they do not contend for PCI bus bandwidth.The more PCI busses  
the better.  
Host CPU Speed  
Faster hosts can typically transfer data quicker.  
Recommendation: Use as fast a processor as possible for the backup system.  
Network Transfer Time  
If backup involves transferring data over the network, network  
performance is often a major bottleneck.  
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Performance Factor  
Detail  
Recommendation: Try not to put Ethernet in the way of data transfer unless staging  
technology is being used; aggregation of multiple Ethernet clients  
remains a good strategy to delivering on drive performance.  
Even with Gbit Ethernet, the effective throughput is less than that of  
an LTO Ultrium 4 drive, so either use carefully designed topologies,  
or stage an image first and use locally attached tape, otherwise the  
Ethernet itself can become the bottleneck.  
Gbit Ethernet can be used in a carefully designed topology.  
Alternatively, stage an image first and then use locally attached tape  
for the backup.  
Write Commands  
Do not interleave write commands with other commands, such as READ  
POSITION and LOG SENSE. Do not, for example, attempt to read the  
TapeAlert log page during a long write.  
Drive-related factors  
Performance Factor  
Detail  
Drive’s SCSI  
Performance  
In order to minimize SCSI bus loading, the drive must execute its SCSI  
phases quickly. The phases are as follows:  
Selection  
Message-out identification  
Receipt of the command  
Disconnection  
Mid-command bus-free time  
Arbitration and reselection  
Message-in identification  
Recommendation: The host must always ensure the following:  
Disconnects are enabled  
Synchronous negotiation is enabled and established between the  
drive and the HBA  
The drive is in buffered mode  
When reading and verifying, always use the same block size as  
that in which the tape is written, otherwise performance will be very  
seriously affected.  
Transfer Mode  
MODE SELECT command.  
Fixed Mode: The transfer size is equal to the (block) size multiplied by  
the number of records (blocks) in the transfer.  
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Performance Factor  
Detail  
Recommendation: A good transfer size to aim at is 256 KB (128 KB minimum). For an  
application that uses 512-byte records, each fixed-mode transfer  
should transfer 512 records. Higher transfer sizes are also  
recommended for higher compression ratios.  
Variable Mode: Only one block is transferred at a time. The size of the  
block determines the size of the transfer. Ideally the application should  
aim to use 256 KB blocks.  
Records (Block) Size  
The size of the transfer impacts the performance, rather than the size of  
the record (blocks) in the transfer.  
Recommendation: As above, aim to use 256 KB transfers. Higher transfer sizes are also  
recommended for higher compression ratios.  
Transfer Size  
Transfer size is the amount of data transferred for a single command,  
whether the drive is in fixed or variable block mode.  
In both fixed and variable modes, the drive works best if it receives a  
large amount of data for each command, so a large transfer size for  
write commands is recommended.  
At small block size, the transfer rate is substantially degraded. This is  
because the drive controller and the host spend too much time  
handling SCSI overhead instead of writing data to tape, resulting in  
stream-fails. The block size at which this happens varies between  
drives, but generally the faster the drive, the larger the block size  
needed to stream.  
Recommendation: Use 256 KB transfers as a minimum. Higher transfer sizes are also  
recommended for higher compression ratios.  
Transfer Direction  
There are some noticeable performance differences between reads  
and writes, caused by the extra device CPU time needed by the drive  
to read data sets from the media.  
Recommendation: Use large transfer sizes; the drive is less likely to stream-read small  
transfer sizes than it will when writing transfers of the same sizes.  
Format-related factors  
Performance Factor  
Tapemarks  
Detail  
Tape marks (filemarks) have many different uses to give a logical  
structure to data on a tape. The SCSI Standard specifies certain actions  
that the drive must take when it is told to write a filemark.  
If the drive is told to write a filemark when the Immediate bit is not set,  
the standard insists that the drive must flush all data to tape. If used  
unnecessarily this will adversely affect performance and waste tape  
capacity.  
Recommendation: Write filemarks as rarely as is reasonable for your application.  
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34 Factors affecting performance  
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5 Supporting Ultrium features  
This section covers the following features of HP Ultrium drives:  
LTO Cartridge Memory page 35  
Automation and drive interface (ACI and ADI) page 35  
Cleaning page 50  
Resetting drives page 50  
Backup software page 50  
Controlling data compression page 51  
Other Mode page information page 51  
Cartridge Memory (LTO-CM)  
LTO Cartridge Memory (LTO-CM) is EEPROM memory that is embedded in every LTO Ultrium tape  
cartridge. It is non-volatile and is contactless in that it is read by RF coupling rather than electrical  
contact.  
Further information  
For general information about LTO-CM, see “LTO Cartridge Memory” in Chapter 5, “Cartridges”  
in Background to Ultrium Drives, Volume 6 of the Ultrium Technical Reference Manual.  
For suggestions of how to make use of cartridge memory in libraries, see “Using Cartridge  
Memory” in “Using Special Features in Libraries, Chapter 2 of the Hardware Integration Guide,  
Volume 1 of the HP LTO Ultrium Technical Reference Manual.  
Automation interface  
The interface between the tape drive and the library will support both the open standard  
Automation/Device Interface (ADI) and the proprietary Automation Control Interface (ACI). The tape  
drive defaults to the ACI protocol and will only transition to ADI when the library initiates an ADT  
login exchange.  
NOTE: The same connector is used for both interfaces; for convenience, it is referred to as the ADI  
Connector in this manual.  
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Automation/Device Interface (ADI)  
There are two elements to the Automation/Device Interface (ADI):  
ADI Transport Protocol (ADT)—a standard protocol for communication between a SCSI  
automation device and a SCSI data transfer device, such as a tape drive.  
The ADT protocol allows conforming ADI SCSI devices to inter-operate. The objectives of ADT  
are:  
• To provide a low-cost interconnect method between an automation device and the data  
transfer devices that reside within the media changer.  
• To standardize this interface so that different disk drives, tape drives, optical media drives,  
and other SCSI devices may be added to conforming media changers without requiring  
modifications to generic system hardware.  
• To provide for the addition of special features and functions through the use of  
vendor-specific options.  
The interface protocol includes provision for the connection of two SCSI ports. One of these ports  
is intended to be attached to a media changer device and may operate either as a SCSI initiator  
port or a SCSI initiator/target port. The other port is intended to be attached to a data transport  
type device (tape drive) and may operate as either a SCSI target port or SCSI initiator/target  
port. No provision is made for connection of more than two ports.  
ADI Commands (ADC-2)—an extension to the SCSI command set for communication with  
application clients through the ADI.  
The objectives of ADC-2 are:  
• To permit an application client to communicate over a SCSI service delivery subsystem, with  
a logical unit that declares itself to be an ADI device in the Peripheral Device Type field of the  
standard INQUIRY data.  
• To define commands unique to the ADI device type.  
• To define commands and parameters to manage the operation of the ADI device type and  
the operation of logical units of other specific device types that are present in the same  
device as the ADI logical unit.  
For details of HP’s implementation of these standards, see the HP ADI Firmware Integration Guide.  
The T10 standards referenced by this guide are as follows:  
ADT: ANSI INCITS 406-2005  
ADC-2: T10/1741-D revision 7d.  
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Automation Control Interface (ACI)  
The Automation Control Interface (ACI) protocol allows the activities of the drive to be coordinated  
within a library. The protocol has been designed so that it can be made into a standard feature of  
tape drives. It provides a rich and extensible functionality to allow automation manufactures to add  
value in their application of it.  
The interface is a serial bus with additional control lines, designed to connect the Ultrium tape drive  
to an automation controller in a tape library. Each tape drive position has a separate ACI  
connection allowing communication to the drive via its RS 422 serial port.  
The ACI protocol provides the following fundamental functions:  
Coordinating the automation controller and the tape drive for Load and Unload operations  
Allowing the automation controller to retrieve information from the tape drive  
Setting tape drive configuration information  
In addition, the following functions may be supported depending on the way that the tape library is  
configured:  
Providing upload and download of firmware images  
Providing access to Cartridge Memory contents  
Providing a protocol for passing SCSI commands to the tape drive over the interface.  
The ACI protocol allows for “packetized” SCSI commands to be sent from the attached controller  
and submitted to the tape drive as if they have been received on the drive’s own SCSI bus. For  
example, the ACI protocol allows the sending of load/unload commands from a specially defined  
automation command set to cause drive action. This ability enables the attached controller to access  
and control the drive in exactly the same way as it would over the SCSI bus.  
NOTE: Ultrium SCSI Parallel drives implement a limited subset of the SCSI commands, including  
INQUIRY, LOG SENSE, LOG SELECT and MODE SENSE.  
The following notes should be regarded as supplementing the ACI protocol specification rather than  
replacing them. Please refer to the specification for further implementation details. These notes refer  
to the “standard” automation drive variant. Different behavior may be exhibited in certain areas for  
specific OEM variants as requested by OEMs.  
Modes of usage through ACI  
Slave to a library controller  
command set to control the action of the drive.  
Most tape libraries need to have a means of communication between controller and tape drives, to  
enable correct synchronization of mechanical operations between drive and picker arm. For  
instance, in a soft load capable device such as an Ultrium drive, the picker must let go of the  
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cartridge at the moment that the drive starts to pull it into the drive, if it is configured for that type of  
operation.  
This degree of control over synchronization cannot be achieved though the host’s backup software;  
it must be controlled directly by the library controller. Most tape libraries work this way today. The  
process is transparent to the backup software.  
SCSI pass-through mode  
The ACI protocol allows the transfer of “packetized” SCSI commands from an attached controller  
and submit them to the tape drive as if they have been received on the drive’s own SCSI bus. This  
enables the attached controller to access and control the drive in exactly the same way as it would  
via the SCSI bus.  
ACI command set  
The following ACI commands are supported on HP Ultrium drives:  
Mandatory Commands Optional Commands  
00h Get Drive Info  
40h Send SCSI Command  
42h Send Firmware Image  
43h Get Firmware Segment  
49h Get Buffer Size  
4Ah Send Firmware Segment  
4Bh Set Time  
01h Load  
02h Unload  
03h Get Drive Status  
04h Set Drive Configuration  
05h Get Drive Configuration  
06h Reset  
4Ch Get Time  
07h Set Baud Rate  
08h No Op  
09h Get Error Info  
0Ah Acknowledge Attention  
ACI commands that affect drive streaming performance  
Commands that alter the state of the drive in some way will affect the performance of the drive when  
stream reading or writing. It is recommended that no command within the following set are sent to  
the drive while the drive is writing or reading as it would affect the data throughput to or from the  
drive:  
Load  
Unload  
Send Firmware Image  
Send Firmware Segment  
Reset  
Set Drive Configuration—if the host (SCSI or FC) is reconfigured  
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Send SCSI with the following opcodes:  
Log Select  
Mode Sense  
Read Attribute  
Write Attribute  
Mode Select  
Request Sense  
New features in ACI 4.3  
The following sections describe the differences between revision 4.2 of the ACI specification, used  
in HP LTO Ultrium 3 drives, and revision 4.3, used in HP LTO Ultrium 4 tape drives.  
The main additions to ACI 4.2 revision are:  
Improved backward compatibility  
Support for encryption  
Backward compatibility  
To provide backward compatibility with ACI 4.0, SCSI parallel drives initialize in ACI 4.0  
compatibility mode. Similarly, Fibre Channel drives initialize in ACI 4.1 compatibility mode and  
SAS drives initialize to ACI 4.2 compatibility mode. This means drives with ACI 4.0, ACI 4.1 or ACI  
4.2 can be replaced with drives with ACI 4.3, without the need to replace or update the automation  
controller firmware.  
In ACI 4.0 compatibility mode the drive will accept Set Drive Configuration CMD_DATA in ACI  
4.0 format and will respond to Get Drive Status and Get Drive Configuration with ACI 4.0  
RDATA.  
In ACI 4.1 compatibility mode the tape drive will accept Set Drive Configuration in ACI 4.1  
format and will respond to Get Drive Status and Get Drive Configuration with ACI 4.1 RDATA.  
In ACI 4.2 compatibility mode the tape drive will accept Set Drive Configuration in ACI 4.2  
format and will respond to Get Drive Status and Get Drive Configuration with ACI 4.2 RDATA.  
An ACI compatibility mode does not restrict the use of ACI 4.3 commands or the use of new fields  
to earlier ACI version commands and will respond with the appropriate ACI 4.3 RDATA in these  
cases.  
A parallel SCSI tape drive will remain in ACI 4.0 compatibility mode until it receives a valid ACI  
4.1 format Set Drive Configuration command or an ACI 4.2/4.3 format Set Drive Configuration  
command with the ACI Major/Minor Version fields set to a new and valid ACI version (which is  
42h). It will then respond with the appropriate ACI version RDATA. The drive will return to ACI  
4.0 compatibility mode in the following circumstances:  
• If the tape drive receives a valid ACI 4.0 format Set Drive Configuration command.  
• An ACI 4.2 or ACI 4.3 format Set Drive Configuration command with the ACI Major/Minor  
Version fields set to 40h.  
• The tape drive is reset.  
A Fibre Channel tape drive will remain in ACI 4.1 compatibility mode until it receives a valid  
ACI 4.2/4.3 format Set Drive Configuration command with the ACI Major/MinorVersion fields  
set to a new and valid ACI version (which is 42h). It will then respond with the appropriate ACI  
version RDATA. The drive will return to ACI 4.1 compatibility mode in the following  
circumstances:  
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• If the drive receives a valid ACI 4.1 format Set Drive Configuration command.  
• An ACI 4.2 or ACI 4.3 format Set Drive Configuration command with the ACI Major/Minor  
Version fields set to 41h.  
• The tape drive is reset. Fibre Channel tape drives do not support ACI 4.0 compatibility  
mode, so they will only accept ACI version 4.1 and later commands.  
An SAS tape drive will remain in ACI 4.2 compatibility mode until it receives a valid ACI  
4.2/4.3 format Set Drive Configuration command with the ACI Major/Minor Version fields set  
to a new and valid ACI version (which is 43h). It will then respond with the appropriate ACI  
version RDATA. The drive will return to ACI 4.2 compatibility mode in the following  
circumstances:  
• If it receives an ACI 4.2 or ACI 4.3 format Set Drive Configuration command with the ACI  
Major/Minor Version fields set to 42h.  
• If the drive is reset. SAS tape drives do not support ACI 4.0 or ACI 4.1 compatibility mode,  
so they will only accept ACI version 4.2 and later commands.  
HP LTO tape drives support all ACI versions later than their default ACI compatibility mode version.  
For example, Fibre Channel drives default to ACI 4.1 compatibility mode but also support ACI  
version 4.2 and ACI 4.3, which can be selected using the appropriate format ACI Set Drive  
Configuration command.  
Notes  
An HP LTO tape drive supports a two-step initialization sequence. The first step behaves as  
described above; the drive goes through the first step of the initialization sequence and then begins  
to send the <ENQ> character at 10-second intervals. The drive sends the <ENQ> character within  
500 ms of the power-on, drive reset, ACI reset or completion of firmware upgrade.  
Once the drive sends the first <ENQ> character, it will begin the second step of initialization. This  
may take several minutes to complete as it includes rewinding the tape and, optionally, unthreading  
it, if the drive contains a seated cartridge with threaded media.  
During the second step of initialization, the drive will respond to all ACI commands, except Get  
Drive Info, Get Error Info and some Send SCSI commands with BUSY status. The drive will respond  
normally to the Get Error Info command. It will respond normally to the Get Drive Info command  
except that every byte of the Manufacturing Data Code and Serial Number fields will contain the  
value FFh. During initialization the drive supports SCSI commands as in the following table. It  
responds with BUSY status to commands that are unsupported:  
SCSI command  
INQUIRY  
Supported during initialization  
Yes  
No  
Yes  
No  
No  
No  
No  
LOG SELECT  
LOG SENSE  
MODE SELECT  
MODE SENSE  
READ ATTRIBUTE  
RECEIVE DIAGNOSTIC REPORT  
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SCSI command  
Supported during initialization  
REQUEST SENSE  
REPORT DENSITY REPORT  
REPORT LUNS  
Yes  
No  
Yes  
No  
Yes  
No  
SEND DIAGNOSTIC  
TEST UNIT READY  
WRITE ATTRIBUTE  
When the drive has completed the second step of initialization, it will respond normally to all  
supported commands, and it will report the correct Manufacturing Date Code and Serial Number in  
the corresponding fields of the Get Drive Info RDATA.  
HP recommend that automation controllers use the Get Drive Status command to detect the  
completion of the second step of tape drive initialization. After the drive sends the first <ENQ>  
character and until it completes the second step of initialization, it will respond to a Get Drive Status  
command with BUSY status. After the drive has completed the second step of initialization, it will  
respond normally to the Get Drive Status command.  
Encryption support  
For parallel SCSI and SAS drives, the RDATA returned by the Get Drive Status command contains an  
Encryption Status field:  
7
6
5
4
3
2
1
0
0
Vendor Cartridge Prevent Media  
Ready  
Eject  
Ready Cartridge Ready  
Write Protect  
Compression  
Rsvd  
Unique Present  
Removal  
Access  
Tape Activity  
Clean  
Load  
Load  
1
2
Cartridge Type  
Drive  
Error  
Media  
Error  
Clean  
Expired  
Clean  
TapeAlert  
Reserved  
Cleaning  
Required Needed  
3–4  
5
Reserved  
Encryption Status  
WORM  
For FC drives, the RDATA returned is in the following format:  
7
6
5
4
3
2
1
0
0
Vendor Cartridge Prevent Media  
Ready  
Eject  
Ready Cartridge Ready  
Write Protect  
Compression  
Reserved  
Unique Present  
Removal  
Access  
Tape Activity  
Load  
Load  
1
2
Cartridge Type  
Drive  
Error  
Media  
Error  
Expired  
TapeAlert  
Cleaning  
Required Needed  
3
4
Port 0  
Active  
Port 0 Topology  
Port 1 Topology  
Port 0 Speed  
Port 1 Speed  
Port 1  
Active  
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7
6
5
4
3
2
1
0
5
Reserved  
Encryption Status  
WORM  
The Encryption Status bits indicate the current encryption/decryption status of the SSC device server:  
Value  
00b  
01b  
Meaning  
The device server is currently not performing encrypting or decrypting operations.  
The device server is currently performing encrypting or decrypting operations.  
10b, 11b Reserved.  
Further details  
For more information about ACI, see the ACI Specification supplied by HP.  
Supporting the ACI protocol  
Software vendors implementing support for attached library devices will need to work closely with  
the library vendor concerned. See HP’s “Ultrium Automation Cookbook” for more details.  
Recommended ACI time-out values  
ACI commands fall into three broad classes:  
Commands that the drive executes immediately  
Commands that the drive queues but which it can execute concurrently with auto-mode reads  
and writes (in other words, streaming operation)  
Commands that the drive queues but which interrupt streaming operation.  
The response time to an ACI command will depend on the type of ACI command and the activity  
status of the drive at the time the command is received.  
Note that the drive does not support ACI command queuing. However, under exception conditions,  
command queuing may occur, say if the automation controller had timed-out the tape drive’s  
response to a command and either resent the command or sent another command. In these  
circumstances, the drive will not ignore the overlapped commands but will respond to every  
command package it had received.  
An example of when this may occur if the host issued a long SCSI ERASE command to the drive and  
the automation controller issued an UNLOAD command, then the drive would not respond to the  
UNLOAD command until the long erase had completed. If the automation controller timed out the  
drive’s response to the UNLOAD command and re-sends the command or sends another command,  
then it needs to be able to handle the response to the original UNLOAD command as well as to the  
subsequent commands.  
The following tables list the recommended ACI command time-outs for queued and non-queued  
commands.  
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Table 1 Non-queued ACI commands  
ACI Command  
Get Drive Info  
Get Drive Status  
Get Drive Configuration  
Get Error Info  
Get Buffer Size  
No Op  
Acknowledge Attention  
Recommended time-out value  
5s  
5s  
5s  
5s  
5s  
5s  
5s  
Table 2 Queued ACI commands  
ACI Command  
Recommended time-out value  
ACI Load—immediate  
ACI Load—non-immediate (drive idle, unloaded)  
ACI Unload—immediate  
5s  
300s  
5s  
ACI Unload—non-immediate (tape loaded, at EOM,  
drive idle)  
300s or 9000s depending on  
implementation strategy  
Set Drive Configuration (tape loaded, at EOM, SCSI  
unload)  
300s or 9000s depending on  
implementation strategy  
ACI Reset—ACI bus  
ACI Reset—drive  
Set Baud Rate  
5s  
5s  
5s  
Treatment of reserved fields  
To ensure forwards compatibility with future versions of the ACI, automation controller firmware  
should set any command fields labelled as ‘Reserved’ to zero. Likewise, automation controller  
firmware should mask off any response fields labelled as ‘Reserved’ during the processing of tape  
drive responses. This will allow older versions of automation controller firmware to operate  
successfully with newer versions of tape drive firmware.  
Recommended power-up sequence  
After power-up, HP recommends that the automation controller wait until it has received at least one  
ASCII <ENQ> character from the tape drive before attempting a command-response transaction. HP  
Ultrium tape drives use a two-step power-up sequence and the drive sends <ENQ> to signal the  
reset state after receiving power. Note that the default baud rate at power-up is 9600.  
Consider sending Get Drive Info as the first command, either packetized or primitive. This retrieves a  
variety of useful identifying information identifying the tape drive, including the version of the ACI  
protocol that the tape drive supports.  
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During the second step of the power-up sequence, the tape drive will respond with BUSY status to all  
ACI commands except Get Drive Info and Get Error Info. The amount of time taken by this second  
step will vary widely depending on three factors:  
The presence or absence of a cartridge in the tape drive  
The position of the media if a cartridge is present  
The ability of the tape drive to access the cartridge memory if a cartridge is present  
HP recommends that the automation controller polls using the Get Drive Status command to monitor  
the completion of the power-up sequence. When the tape drive returns GOOD status to a Get Drive  
Status command, it has completed the power-up sequence.  
If operating with a tape drive that supports ACI V4.1 and higher, HP recommends that the  
automation controller synchronizes the tape drive’s time stamping clock to its own using the Set Time  
command once the tape drive has completed the power-up sequence.  
In some circumstances when responding to the first Get Drive Info command, the tape drive will fill  
every byte in the Manufacturing Date Code and Serial Number fields with FFh. The tape drive  
behaves this way when it receives the Get Drive Info command during the second step of the  
power-up sequence because it cannot access the EEPROM that stores this information at that time.  
The automation controller may retrieve the correct value for these fields with a second Get Drive Info  
command sent after the power-up sequence completes.  
Once the power-up sequence completes, the automation controller can configure the tape drive  
using the Set Drive Configuration command. Each time a Set Drive Configuration command is sent,  
it is recommended that a Get Drive Configuration command is sent to double-check that the drive is  
configured correctly.  
It is recommended that the Get Buffer Size command is sent to drive as part of the power-up  
sequence to determine the maximum burst buffer size and maximum receive/transmit package  
buffer sizes.  
If a baud rate other than the default is to be used, then it is recommended that this is set during the  
power-up sequence using the Set Baud Rate command.  
Recommended load-unload configuration  
The Set Drive Configuration command provides access to several features that alter the tape drive’s  
behavior when loading or unloading cartridges. These give a large amount of flexibility in  
designing an automation controller.  
HP’s experience suggests that certain configurations result in significantly fewer difficulties when  
integrating the HP Ultrium tape drive.  
HP recommends configuration with the Auto-Eject feature disabled. If Auto-Eject is enabled, the drive  
will eject a cartridge in a variety of cases not directly controlled by the automation controller. These  
include receiving a SCSI LOAD/UNLOAD command with the Load bit set to 0, various load failures  
(regardless of the method of instigating the load), completion of the image verification step when  
upgrading the tape drive’s micro-code using a firmware upgrade cartridge, and completion of a  
head-cleaning cycle when using a cleaning cartridge. These ejects can result in both the automation  
controller and the tape drive losing track of the location of the cartridge.  
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HP recommends configuration of the upgrade protect features to enabled. (the Upgrade Protect bit  
of the Set Drive Configuration command is set to 1). This will ensure that if a firmware upgrade  
cartridge is loaded inadvertently, the drive’s micro-code will not be upgraded unnecessarily.  
If requested, HP will alter the default settings for Auto-Eject, Auto-Load, Auto-Thread, Clean Protect,  
and Upgrade Protect features in your particular variant of the firmware.  
Recommended Get Drive Status polling frequency  
HP recommends that the polling frequency of a Get Drive Status command should be in the range  
2–5s, particularly during cartridge loading and unloading. This frequency should be sufficient to  
capture state changes in the drive while not adding significant processing overhead to the drive or  
automation controller.  
ACI protocol communications retry  
The ACI protocol specifies a comprehensive packet retry mechanism. Under certain timing  
conditions, especially for automation controllers that use a single microprocessor and multiplex the  
ACI communications from one tape drive to another, the automation controller can receive a  
response packet from the tape drive that it does not need. When this situation arises, the automation  
controller should send a positive acknowledgement control character, <ACK>, to the tape drive and  
discard the packet. Since the tape drive receives the <ACK>, it will not re-send the packet.  
Upgrading the drive firmware  
There are three methods of updating the firmware in the tape drive:  
Firmware upgrade via tape  
It is expected that firmware upgrades via tape will be done under the control of the library controller  
and the Operator Control Panel and independently of the host interface.  
If the Upgrade Protect bit is set to 1 in the Set Drive Configuration command (which is  
recommended), the tape can be loaded into the drive in the usual manner, except that the ACI Load  
command must be sent to the drive and the Upgrade bit and Thread bit in byte 1 of the Load  
command must be set to 1.  
If the Immediate Response bit in the ACI Load command is not set to 1 and the firmware upgrade  
failed (say due to an invalid image on the tape), the ACI Load command will report a CHECK  
CONDITION with appropriate sense key and additional sense.  
If the Immediate Response bit is set to 1 and the firmware upgrade fails, the automation controller  
can detect the failure by noting that the Tape Activity field in the Get Drive Status response returns to  
Idle and the tape drive does not enter its ACI initialization procedure.  
While the drive is preparing to upgrade the firmware, it will report Tape Activity = “Code  
Update in Progress.  
While it is actually upgrading the firmware, the drive will not respond to ACI commands.  
After the firmware upgrade has completed the drive will reset and send out an ENQ byte over  
ACI.  
After performing a firmware upgrade via tape it is recommended that the library controller checks  
that an ENQ byte is sent by the drive after it power-cycles at the end of the firmware upgrade  
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process and that the normal power-up ACI command sequence is followed to ensure that the drive is  
configured correctly and to verify the firmware version and ACI version.  
Firmware upgrade via the primary host interface  
The library controller will not have direct visibility if a firmware upgrade of the tape drive is initiated  
via SCSI, hence it is recommended that the controller monitors for the that a firmware upgrade is  
taking place or has taken place.  
While the firmware image is being sent to the drive via SCSI, the drive responds to ACI  
commands with status BUSY.  
When the drive is actually upgrading the firmware, it will not respond to ACI commands.  
When the firmware download is complete, the drive will reset itself and send an ENQ control  
character.  
It is recommended that the same ACI command sequence be followed as if the drive had been  
power-cycled to ensure that the drive is configured correctly and to verify the firmware version and  
ACI protocol version.  
Firmware upgrade via ACI  
Two methods exist for updating firmware via ACI:  
Using the Send Firmware Image command. The automation controller sends the firmware image  
in one data burst outside a normal packet.  
Using the Send Firmware Segment command. The automation controller sends the firmware  
image in multiple packets.  
HP intends to make the Send Firmware Image command obsolete in a future version of the ACI.  
Please use the Send Firmware Segment command in all new development. See the ACI specification  
for further details of both commands.  
When the firmware download is complete, the drive will reset itself and send an ENQ control  
character. It is recommended that the same ACI command sequence be followed as if the drive had  
been power-cycled to ensure that the drive is configured correctly and to verify the firmware version  
and ACI version.  
Library firmware upgrade via tape  
The ACI specification allows for upgrading the automation controller firmware via tape. This  
functionality is not supported in current releases of drive firmware and will be added at a later date  
subject to customer needs.  
Handling irregular cartridges  
The purpose of this section is to indicate what can be seen over the ACI protocol if the host issues a  
MOVE MEDIUM command to the library when an irregular cartridge (such as a cleaning cartridge,  
expired cleaning cartridge, Ultrium 4 cartridge, or defective data cartridge) is in the storage  
element.  
The following descriptions assume that the auto-eject bit in the Set Drive Configuration command  
has been set to 0 so that the cartridge will not be ejected from the drive unless an ACI Unload  
command is issued with the Eject bit set to 1.  
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Cleaning cartridge (HP-configured or Universal)  
When a valid cleaning cartridge (one that has not expired) is loaded, behavior depends on the  
Clean Protect bit of the Set Drive Configuration command.  
Clean Protect = 1 f the Clean Protect bit is set to 1, the drive will not thread the tape or clean the  
drive until an ACI Load command with the Clean bit set to 1 is sent to the  
drive. If the Load command is sent without the Clean bit set the drive will return  
a CHECK CONDITION. Also, if the “cleaning cartridge” is not in fact a cleaning  
cartridge, the Load command with the Clean bit set to 1 will produce a CHECK  
CONDITION.  
Clean Protect = 0 If the Clean Protect bit in the Set Drive Configuration command is set to 0, the  
drive will thread the tape and clean the drive when a cleaning tape is loaded.  
When the cleaning cartridge is seated in the drive, the ‘cartridge type’ field in  
the Get Drive Status RDATA will be set to 06h (cleaning).  
While the drive is cleaning, the Cleaning bit in the Get Drive Status RDATA will  
be set to 1 and the Tape Activity field will be set to Ah (cleaning).  
When cleaning has finished, if Auto-Eject is disabled, the cartridge will be in  
the ready eject position with the Cartridge Present, Write Protect, Ready Eject,  
and Ready Load bits set to 1, Cartridge Type = ‘Cleaning, and  
Tape Activity = ‘Idle. The cartridge can now be unloaded from the drive.  
Expired cleaning cartridge (HP-configured or Universal)  
If an expired cleaning cartridge is loaded into the drive, the cartridge will be placed in the ready  
eject position with the Cartridge Present, Write Protect, Ready Eject, Ready Load, Media Error,  
TapeAlert, and Clean Expired bits set to 1, Cartridge Type = ‘Cleaning, and Tape Activity = ‘Idle.  
TapeAlert flag 22h will be set.  
Non-HP Ultrium 1 cleaning cartridge  
If a non-HP Ultrium 1 cleaning cartridge is loaded into the drive, the cartridge will not be  
recognized as a supported cartridge. The cartridge will be placed in the ready eject position with  
the Cartridge Present, Write Protect, Ready Eject, Ready Load, Media Error, and TapeAlert bits set to  
1, Cartridge Type = ‘Unknown, and Tape Activity = ‘Idle. TapeAlert flag 17h will be set.  
Unreadable data cartridge  
If a data cartridge is loaded that cannot be read, the cartridge will be placed at the ready-to-eject  
position with the Cartridge Present, Write Protect, Ready Eject, Ready Load, Media Error, and  
TapeAlert bits set to 1, Cartridge Type = ‘Unknown, and Tape Activity = ‘Idle. TapeAlert flag 05h  
will be set.  
Ultrium 5 and later data cartridges  
If an Ultrium 5 or later data cartridge is loaded into the drive, the drive will recognize the cartridge  
as a non-supported cartridge. The cartridge will be placed at the ready-to-eject position with the  
Cartridge Present, Write Protect, Ready Eject, Ready Load, Media Error, and TapeAlert bits set to 1,  
Cartridge Type = ‘Unknown, and Tape Activity = ‘Idle. TapeAlert flag 0Ch will be set.  
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Data cartridge with unreadable CM  
If the Cartridge Memory cannot be read, the drive assumes that the cartridge is not supported. If the  
cartridge is loaded into the drive, it will be placed at the ready-to-eject point with the Cartridge  
Present, Write Protect, Ready Eject, Ready Load, Media Error, and TapeAlert bits set to 1, Cartridge  
Type = ‘Unknown, and Tape Activity = ‘Idle. TapeAlert flag 0Fh will be set.  
Cartridge fails to seat or load  
If a cartridge fails to seat or load, it will be placed at the ready-to-eject position with the Cartridge  
Present, Ready Eject, Ready Load, Media Error, and TapeAlert bits set to 1, Tape Activity = ‘Idle.  
TapeAlert flag 04h will be set. If the cartridge type is recognized, this will be indicated in the  
Cartridge Type field, otherwise the field will indicate Cartridge Type = ‘Unknown.  
Cartridge cannot be loaded  
HP recommends that GOOD status is not returned to the host for the MOVE MEDIUM command until  
the library controller has seen the Cartridge Load bit in the Get Drive Status RDATA set to 1. If the  
library controller does not see this bit set, HP recommends invoking an appropriate load re-try  
algorithm. After re-trying the load, if this bit is still not set to 1, assume that there is a problem with  
the cartridge. HP recommends that the library controller responds to the MOVE MEDIUM command  
with CHECK CONDITION, a sense key of Not Ready and additional sense of 5300 (media load or  
eject failure), and then moves the cartridge back to the source element. If the Drive Error bit is set to  
1 in the Get Drive Status RDATA, appropriate actions should be taken.  
Valid firmware upgrade cartridge  
If a firmware upgrade cartridge with a valid firmware image is loaded, and neither the library  
controller nor the host knows that the cartridge is a firmware upgrade cartridge, what occurs  
depends on the Upgrade Protect bit in the Set Drive Configuration command.  
Upgrade Protect = 1 If the Upgrade Protect bit in the Set Drive Configuration command is set to 1,  
it is assumed that the Upgrade bit in the Load command will be zero and no  
firmware upgrade will be performed. The cartridge will be placed at the  
ready-to-eject position with the Cartridge Present, Write Protect, Ready Eject,  
Ready Load, Media Error, and TapeAlert bits set to 1, Cartridge Type =  
‘Firmware Upgrade, and Tape Activity = ‘Idle. TapeAlert flag 10h will be set.  
Upgrade Protect = 0 If the Upgrade Protect bit in the Set Drive Configuration command is 0, a  
firmware upgrade will be performed on the drive. While the drive is  
preparing to upgrade the firmware, it will report Tape Activity = “Code  
Update in Progress. When actually upgrading the firmware the drive will not  
respond to ACI commands. After the firmware upgrade has completed the  
drive will reset and send out an ENQ byte over ACI.  
It is recommended that the library controller follows the normal power-up ACI  
command sequence after receiving the ENQ byte to ensure that the drive is  
configured correctly and to verify the firmware version and ACI version.  
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Invalid firmware upgrade cartridge  
If a firmware upgrade cartridge with an invalid firmware image is loaded, and neither the library  
controller nor the host knows that the cartridge is a firmware upgrade cartridge, again what occurs  
depends on the Upgrade Protect bit in the Set Drive Configuration command.  
Upgrade Protect = 1 If the Upgrade Protect bit in the Set Drive Configuration command is set to 1,  
it is assumed that the Upgrade bit in the Load command will be zero and no  
firmware upgrade will be performed on the drive. The cartridge will be  
placed at the ready-to-eject position with the Cartridge Present, Write  
Protect, Ready Eject, Ready Load, Media Error, and TapeAlert bits set to 1,  
Cartridge Type = ‘Firmware Upgrade, and Tape Activity = ‘Idle. TapeAlert  
flag 10h will be set.  
Upgrade Protect = 0 If the Upgrade Protect bit in the Set Drive Configuration command is set to 0,  
the firmware upgrade process will start and the drive will thread the tape  
and read the image. During this time, the drive will report Tape Activity =  
“Code Update in Progress. When the image has been read the drive will  
check whether the image is valid. As in this case the image is not valid, the  
drive will place the drive at the ready-to-eject position with the Cartridge  
Present, Write Protect, Ready Eject, Ready Load, Media Error, and TapeAlert  
bits set to 1, Cartridge Type = ‘Firmware Upgrade, and Tape Activity =  
‘Idle. TapeAlert flags 10h and 22h will be set. The drive will not send out an  
ENQ byte and will not reset.  
Frequently asked questions  
ACI protocol allows activities of the drive to be co-ordinated within a library. It provides several  
modes for operating HP Ultrium drives within tape libraries. In addition, the Cartridge Memory can,  
at the very minimum, provide an ‘electronic barcode’ facility to allow media tracking. HP is working  
with all the major tape library vendors to ensure that the full potential of these features are realized,  
and recognizes that ISV software support is a key part of this process. In advance of the release of  
the HP Ultrium Automation Cookbook, here are answers to some frequently asked questions:  
Is there separate firmware for drives intended to go into libraries?  
Specific variants of the firmware for automation drives enable the automation interface, which is not  
enabled in standalone drives. Otherwise the code is similar. A variant can only be downloaded if it  
matches the variant in the drive.  
Cleaning  
The tape drive tells the automation controller that a cleaning tape needs to be used through two bits  
in the ACI Get Drive Status command. The Cleaning Needed bit indicates deterioration in the write  
the drive at the earliest opportunity. Following a successful clean, the Cleaning Needed bit will be  
cleared. The Cleaning Required bit indicates that the drive is unable to read or write unless the drive  
is first cleaned with a cleaning tape. It is recommended that a cleaning cartridge is loaded into the  
drive immediately. Following a successful clean, the Cleaning Required bit will be cleared.  
Under normal circumstances, cleaning cartridges can be used for 50 cleanings.  
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Resetting drives  
The tape drive can be reset by the automation controller via the ACI Reset command or, in ACI  
mode, by pulling the ACI_RST_L line low (see “Rear Panel and Connectors, Chapter 7 of the  
Hardware Integration Guide, Volume 1 of the HP LTO Ultrium Technical Reference Manual).  
Resetting via the ACI Reset command  
Two levels of reset via the Automation Interface are provided, namely ACI Reset and Drive Reset. The  
former resets the Automation Interface port and all SCSI parallel/Fibre Channel ports. The latter is  
equivalent to a power-on reset. Either reset method will interrupt the interface between the drive and  
host, with the Drive Reset potentially resulting in no End of Data written to tape.  
It is therefore strongly recommended that an ACI reset command is not sent unless all other recovery  
methods have failed. Note that certain ACI commands (see Table 2 on page 43) can be queued  
behind outstanding SCSI commands giving the impression that the drive has stopped responding  
over the Automation Interface bus. (All command packages will be still be ack'ed even though the  
command will be queued.)  
A SCSI interface reset will not affect the Automation interface.  
NOTE: Following an upgrade of the drive firmware via either tape or SCSI, the drive will be reset  
as if it had been powered up.  
The implementation details are beyond the scope of this document currently.  
Resetting using the ACI_RST_L line  
The behavior when the ACI-RST_L line is activated depends on whether the drive is in ACI or ADI  
mode. In ACI mode activating this line will produce a power-on reset. Activating the ACI_RST_L in  
ADI mode will simply logout the ADT port.  
Further details  
For more information about ACI, see Automation Control Interface (ACI)” in Chapter 1, “Ultrium  
Features, of Background to Ultrium Drives, Volume 6 of the HP Ultrium Technical Manual.  
For more details of hardware integration, see Chapter 5, Automating Drives, of Hardware  
Integration, Volume 1 of the HP Ultrium Technical Manual.  
Backup software  
You need backup application software that supports your Ultrium drive and tape library. For the  
latest list of appropriate backup packages, contact your tape library supplier.  
Suitable backup applications include driver software that establishes the interface between the tape  
drive and the software. Applications usually recognize tape drives by their manufacturers’ ID string  
rather than their model number:  
LTO 4 SCSI drive  
“HP Ultrium 4-SCSI”  
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LTO 4 SAS drive  
LTO 4 FC drive  
“HP Ultrium 4-SCSI” (“SCSI” is not a typo!)  
“HP Ultrium 4-SCSI” (“SCSI” is not a typo!)  
Controlling data compression  
The data compression hardware in HP Ultrium drives can detect whether incoming data is already  
compressed and will not attempt to compress it again. The drive can switch dynamically and  
automatically between compressing and non-compressing modes, thereby optimizing both  
compression ratio performance and data rate. As this mode of behavior is embedded in the Ultrium  
format, there is no need for host application software to switch the drive’s data compression on and  
off and HP strongly recommends to leave data compression at its default of 1 (on). This is set in the  
Select Data Compression Algorithm (SDCA) field of the Device Configuration mode page (page  
10h).  
Host applications may read the Data Compression mode page (0Fh) to determine that the drive is  
capable of data compression; the DCC bit is set to indicate this. HP recommends that the host does  
not attempt to modify either the Data Compression Enable (DCE) or Data Decompression Enable  
(DDE) bits.  
Interpreting the current compression ratio and reporting it through applications is desirable for  
customers so that HP can accurately support customer installations. Without knowing the  
compression ratios achieved, it is difficult for support to suggest whether performance achieved is  
good or merely tolerable for customers’ data. HP recommends reporting compression and includes  
example source code for interpreting this functionality.  
Other mode page information  
Accessing Cartridge Memory without threading the tape  
You can configure Ultrium drives so that when a cartridge is loaded, the Cartridge Memory can be  
accessed without threading the tape. This functionality is set with the Autoload field (byte 5, bits  
0–2) in the Control mode page (0Ah). Zero (default) allows the cartridge to load in a conventional  
way. 001b or 010b allows the media to be loaded but not threaded, so the drive can read the  
Cartridge Memory contents. All other values for this field are reserved.  
Buffer size at EW-EOM  
The Buffer Size at EW-EOM field in the Device Configuration Mode page (10h) is set to zero.  
HP Ultrium tape drives automatically allow sufficient space between EW-EOM and “physical” EOT  
to satisfy backup applications.  
Synchronize at EW-EOM  
The SEW field (byte 10, bit3) on the Device Configuration mode page (10h) specifies how the drive  
behaves when reaching EW-EOM.  
The parameter is fully supported. Default 0: the drive continues to buffer data objects after passing  
EW-EOM. If you require behavior compatible with earlier drive generations, send a MODE SELECT  
command to set this bit to 1.  
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Write delay time  
The Write Delay Time field (bytes 6–7) on the Device Configuration mode page (10h) specifies the  
inactivity delay before the drive will automatically flush its data buffer. A value of 0 is an infinite  
delay; any other value is the delay in 100ms units.  
This parameter is modifiable by a MODE SELECT command. The default value is 12Ch (300d) which  
corresponds to 30s.  
Rewind on reset  
The Rewind on Reset field (byte 15, bits 3–4) on the Device Configuration mode page (10h) allows  
the host control over the action taken in the event of a bus reset.  
If the field is 00 (default) or 10b the logical position is unchanged following a reset. If the field is set  
to 01b the media will be rewound to the logical beginning of media following a bus reset event.  
Partition size  
The Ultrium format only supports a single partition. The Medium Partition Mode page (11h) has no  
changeable fields. In the Device Configuration Mode page (10h), the Active Partition field should  
both be zero since multiple partitions are not supported.  
NOTE: If the SET CAPACITY command is used to create logically shortened media, the partition size  
is updated to reflect the new capacity.  
In the Device Configuration mode page (10h) the Active Partition field must be 0 since multiple  
partitions are not supported.  
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6 Sense keys and codes  
Sense keys—actions to take  
Ultrium drives follow the ANSI definition of sense keys. The following table explains how the  
drives interpret sense key descriptions.  
As sense keys and additional sense codes are intended to be hierarchical errors, the table  
recommends action for the host when a particular sense key is reported.  
For more detailed recovery actions, see Additional sense codes—actions to take” on  
page 57.  
Code Sense Key  
NO SENSE  
Interpretation  
0h  
These are informational/positional codes. The additional sense  
codes are not generally considered errors; they usually indicate  
some condition (such as hitting a filemark). The tape positional  
codes are mandatory for all sequential access devices. This use  
complies with SCSI-2, so it is generic.  
For additional sense codes, see “0h—NO SENSE” on page 58.  
Action: The host will know what to do with this information, depending  
upon the I/O operation at the time. Since the drive implements  
Progress Indication, this sense key may be returned if the drive is  
polled while an immediate operation is in progress.  
If CHECK CONDITION occurs with this sense key, and the additional  
sense code is not recognized by the host, the software should just  
log the occurrence and continue. It will not be considered an error.  
The I/O should have completed without an error.  
RECOVERED ERROR  
1h  
These errors have been recovered by the drive. The drive may  
report any type of recovered error additional sense code.  
RECOVERED ERROR is returned is a MODE SELECT parameter is  
truncated or if a TapeAlert event is being reported.  
RECOVERED ERROR is the lowest priority sense key; it is only  
reported when the I/O has completed with no other type of CHECK  
CONDITION having occurred.  
For additional sense codes, see “1h—RECOVERED ERROR” on  
page 59.  
Console Message: None  
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Code Sense Key  
NOT READY  
Interpretation  
2h  
This sense key generally means the host will have to wait for the  
drive to become READY. Media access is not possible. See  
“3h—MEDIUM ERROR” on page 62. Also see the Media Access  
pre-execution check.  
Action: The host needs to take one of the following actions:  
Wait until the drive becomes available.  
Issue some type of initializing command.  
Perhaps instruct the user to put the drive online.  
The handling of this sense key will depend upon the host’s  
operating system and the additional sense code.  
Console Message: Drive not ready - media access not possible  
MEDIUM ERROR  
3h  
This sense key indicates a failure that is probably due to a problem  
with the tape. The I/O did not complete. The I/O may have been  
partially attempted and data on the tape may have been altered.  
The drive will have retried an optimal number of times before  
reporting this sense key.  
For additional sense codes, see “3h—MEDIUM ERROR” on  
page 62.  
Action: Recovery depends on the operating system or application. At the  
very least, whatever the additional sense code, the software should  
log the error, terminate I/O to the drive, and pass the appropriate  
error to the calling application.  
On read, the driver should discriminate between hard read failures  
caused by the media, and those resulting from an inability to  
decompress data.  
Console Message: On write, ASQ 0C00h  
Write to tape failure  
On write attribute, ASQ 1112h Write to CM failure  
On read, ASQ 70NNh  
Decompression  
exception  
On read attribute, ASQ 1112h Reading CM failure  
On read (otherwise)  
On space  
Read from tape failure  
Failed to locate  
record on tape  
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Code Sense Key  
HW ERROR  
Interpretation  
4h  
5h  
6h  
This indicates that the current I/O operation has failed due to a  
hardware failure.The FRU code in the sense data should indicate  
which part of the hardware is bad. The drive should not be used  
again until corrective action has been taken. Specific recovery  
depends on the operating system and application.  
For additional sense codes, see “4h—HW ERROR” on page 67.  
Action: Whatever the additional sense code, the software should log the  
error, terminate the I/O, and report the appropriate error to the  
calling application. Whether the drive requires any further  
corrective action before it can be used again (such as a reset or  
manual intervention) depends on the additional sense code.  
Console Message: Tape drive hardware failure  
ILLEGAL REQUEST  
The last command sent to the drive, or the data sent because of the  
command, could not be accepted by the drive because it violated  
conditions imposed by the drive.  
For additional sense codes, see “5h—ILLEGAL REQUEST” on  
page 68. Also see the Illegal Command, Illegal Field, Fixed Bit,  
Reservation and Parameter List pre-execution checks.  
Action: The software can retry the I/O, or else it can terminate the I/O and  
report an error to the calling application, particularly if the I/O has  
been retried a number of times and continues to fail with the same  
sense key. The specific retry or recovery strategy depends on the  
operating system.  
Console Message: Illegal SCSI command requested  
UNIT ATTENTION  
The operating conditions of the drive have been changed in some  
manner that the host should be aware of. For example, the drive  
may have gone online or been reset, the Mode parameters may  
have been changed, a second host may have changed the drive’s  
operating conditions, and so on.  
For additional sense codes, see “6h—UNIT ATTENTION” on  
page 69. Also see the Unit Attention pre-execution check.  
Action: Recovery depends on the device class and the additional sense  
code. In general, the software should assume that mode settings  
and so on have been lost, and so should re-initialize the drive. The  
failed command will not have been executed and should be  
repeated.  
Note that for parallel SCSI, the host driver may need to renegotiate  
transfer parameters (for example, by using a PPR message) before  
continuing.  
Console Message: Tape drive operating conditions may have  
changed  
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Code Sense Key  
DATA PROTECTION  
7h  
This is an error if the I/O operation is attempting to access the  
media in some manner and failing because data on the media may  
not be accessed at this time (for example, because the tape is  
write-protected; or the drive is unable to decrypt data because the  
key is incorrect).  
For additional sense codes, see “7h—DATA PROTECTION” on  
page 72.  
Also see the Media Write pre-execution check.  
Action: Depends on the operating system. If this sense key occurs with other  
than an additional sense code of 2700h, the software should log  
the error, terminate the I/O, and then send an error (operating  
system specific) to the calling application. Data on the tape will not  
have been altered.  
Console Message: Media write-protected or encrypted  
BLANK CHECK  
8h  
Bh  
An attempt was made to read unwritten media. Recovery from this  
sense key depends on the operating system. It may be regarded as  
an error because more data was expected by the host, or it may be  
an expected condition.  
For additional sense codes, see “8h—BLANK CHECK” on  
page 74.  
Console Message: End-of-Data encountered  
ABORTED  
COMMAND  
The drive has terminated the command. This could be caused by a  
problem related to the SCSI bus or Fibre Channel link. For example,  
it is reported if a target or LUN receives a second command from  
the same host before the previous command from that host has  
completed.  
For additional sense codes, see “Bh—ABORTED COMMAND” on  
page 75.  
Action: Recovery depends on the additional sense code and the operating  
system. In some cases, the host may want to retry the current I/O. If  
the additional sense code is 4E00h (overlapped commands  
attempted), the host may not want to retry the current I/O because  
the previous I/O will not have been completed.  
Console Message: SCSI protocol problem  
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Code Sense Key  
VOLUME  
OVERFLOW  
Dh  
Data could not be written because of a lack of remaining space on  
the tape. See the WRITE and WRITE FILEMARK commands. Recovery  
from this depends on the device class and the operating system. It is  
a “generic” sense key—the host should be able to recover from it  
without knowing the additional sense code.  
For additional sense codes, see “Dh—VOLUME OVERFLOW” on  
page 76.  
Console Message: Physical End-of-Tape reached, unable to fit  
remaining information on tape  
Additional sense codes—actions to take  
These tables provide information about sense data, so that software can know which  
additional sense codes can be reported under which sense keys. It is important that the  
operating system makes all Request Sense data available to applications and, in interpreted  
form, to the end-user.  
Actions are suggested for software to use when determining the recovery action for different  
sense keys and additional sense code and qualifying codes (ASC/ASCQ).  
It is strongly recommended that the operating system and/or application use the entire  
ASC/ASCQ data to determine the appropriate recovery action.  
The tables are in numerical order, not order of priority. That is, they do not suggest which sense  
keys should be checked first, nor do they recommend priorities for the devices to report errors.  
NOTE: When the sense, additional sense code and qualifying sense keys are listed, the  
software may look at all three keys to determine action. The drive should use that exact  
combination to report that particular error.  
For example, a drive will report that it is not ready when there is no cartridge present by setting  
the sense key to NOT READY with additional sense of 0402h (LUN not ready, initializing  
command required). No other combination of sense key and additional sense may be used to  
report that particular condition.  
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0h—NO SENSE  
The following action applies to most additional sense codes in this group:  
Action: For all additional sense codes except 82 82h, the action of the software depends on  
the current I/O and what the operating system has been expecting. Recovery  
depends on the operating system. As a minimum, the software should pass an error  
to the calling application indicating the positional mark that has been encountered.  
The I/O can be retried if desired.  
Code Meaning  
Comments  
00 00 No additional sense  
The drive has no additional sense information for the  
host. The flags in the sense data indicate the reason for  
failure.  
Action: see above  
00 01 Filemark detected  
This indicates one of the following:  
A READ or SPACE command was terminated early  
because a filemark was encountered.  
Unsolicited Positional Sense has been set to indicate  
“at a filemark.  
The Mark bit in the sense data will always be set.  
Action: see above  
00 02 End of Tape detected  
A command completed early because End of Tape or the  
physical end of the tape was encountered.  
The EOM flag in the sense data will be set.  
Action: see above  
00 04 Beginning of Tape detected BOT was encountered during a space command.  
00 16 Operation in progress The command is in progress and has not yet completed.  
00 18 Erase operation in progress This could be because another host initiated the  
00 19 Locate operation in  
00 1A progress  
command; or the command was sent in immediate  
mode. The Sense Key Specific Value field in the sense  
data will give some indication of how far the operation  
has progressed.  
Rewind operation in  
progress  
Action: Either wait for the command to complete, or poll again  
to see how it is progressing.  
82 82 Drive requires cleaning  
The drive has detected that the heads need to be  
cleaned to maintain good operation.  
Action: Optionally, log the occurrence for information. It will not  
be considered an error and the software will continue.  
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1h—RECOVERED ERROR  
NOTE: Reporting of recovered errors defaults to OFF.  
Action: In all cases, action depends on the device class and operating system.  
Code Meaning  
Comments  
37 00 Rounded parameter  
The drive needs to round off the value of a parameter  
sent by MODE SELECT because it cannot store it to the  
degree of accuracy sent by the command.  
5D 00 Failure prediction threshold Failure Prediction thresholds have been exceeded  
exceeded  
indicating that TapeAlert flags have been activated.  
Action: Retrieve the TapeAlert log page to find out which flag  
has been activated and advise the user accordingly.  
5D FF Failure prediction threshold The Informational Exceptions Mode page has been sent  
exceeded (false)  
with the Test field set to 1 and the DExcpt field to 0,  
causing the drive to generate a false informational  
exception condition (a false device failure).  
Action: Since the function of the Test field is simply to test that an  
informational exception condition will produce a CHECK  
CONDITION and that the exception will be reported to  
the TapeAlert log, no action is necessary.  
2h—NOT READY  
Code Meaning  
Comments  
04 00 LUN not ready, no cause This is set if an unload is occurring with immediate report  
to report  
on, or initiated through the front panel, or a different host  
initiated the command. It is present for the duration of  
the unload or eject, after which the additional sense  
changes to 3A 00h (medium not present) or 0402h  
(logical unit not ready, initializing command required).  
Action: 1. Issue a message to the console stating that the tape is  
currently being unloaded from the drive.  
2. Poll the drive until the additional sense changes to  
3A 00h or 04 02h.  
and the previous sequence of commands.  
4. Depending on the application, the software may  
terminate the current I/O.  
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Code Meaning  
Comments  
04 01 LUN in process of  
A media access command has been received while a  
load is occurring with immediate report on, or initiated  
through the front panel, or a different host initiated the  
command.  
becoming ready  
Action: 1. Effectively poll the drive by re-sending the command  
until the media is loaded, when UNIT ATTENTION with  
additional sense of 28 00h will be set if the tape was  
inserted via the front panel. Otherwise poll the drive  
(TUR) until GOOD status is reported. At this point the  
command can be executed.  
2. Report to the console that the drive is in the process  
of loading tape.  
04 02 LUN not ready, initializing A cartridge is present in the drive but is not logically  
command required  
loaded.  
Action: 1. The software must issue a LOAD before media access  
is permitted.  
2. Issue a message to the console to request a  
user-initiated load, or to indicate drive status, or both.  
04 07 Command in progress  
The tape drive is currently executing an immediate mode  
command.  
04 0C LUN not accessible, port in The command is not available on the specified logical  
unavailable state  
unit when sent to the drive through the specified port.  
04 12 Logical unit offline  
The command cannot be executed because the specified  
logical unit has not yet been configured via the  
appropriate port.  
0B 01 Thermal limit exceeded  
There has been a failure due to the drive temperature  
being outside the acceptable range.  
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Code Meaning  
Comments  
30 03 Cleaning cartridge  
A medium-access command has been sent to the drive  
while a cleaning cartridge was loaded.  
installed.  
Action: 1. Terminate the current I/O, and return the appropriate  
error.  
2. Send a message to the console indicating that a  
cleaning cartridge is in the drive and a cleaning  
cycle is being performed.  
3. Prompt the user to wait for the cartridge to be  
ejected. In a library, the cartridge will be ejected  
when requested by the library or host. In an internal  
or external single drive, the cartridge will be ejected  
automatically.  
4. Prompt the user to proceed with the next  
application-specific activity.  
5. Log the cleaning cycle in the system log.  
3A 00 Medium not present  
A medium-access command has been received when no  
cartridge is in the drive.  
Action: As a minimum, issue a message to the console  
indicating that a drive is present but no tape is loaded.  
3A 04 Medium not present,  
A media access command has been received when the  
Media Auxiliary Memory tape has been loaded but not threaded. This will be  
accessible  
reported if the hold bit of the LOAD CDB was set or the  
Autoload field in the Control mode page is non zero.  
3E 00 Logical unit has not  
This is set during power-up when it is not possible to  
send medium-access commands to the drive because  
mechanism tests are being executed. When the tests are  
complete, the additional sense changes to 3A 00h,  
04 01h or 04 02h depending on whether a cartridge  
was present at power-on.  
self-configured yet  
Action: 1. Issue a message to the console indicating that the  
drive is powering up.  
2. Effectively poll the drive until the drive transitions to  
another state, at which point either execute the  
command or terminate the I/O.  
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3h—MEDIUM ERROR  
Code Meaning  
Comments  
00 02 End of Tape detected  
A READ, SPACE, WRITE or WRITE FILEMARKS command  
found EOT unexpectedly. This typically occurs when a  
drive cannot locate the target object on tape because the  
block count is too great.The EOM flag will be set.  
Action: 1. Recovery action depends on the initiating action. As a  
minimum, tell the calling application that physical  
EOP/M has been encountered. Also display this  
information as a console message.  
2. Send any residue information to the calling  
application.  
0C 00 Write error  
The drive has failed to write data or filemarks to tape.  
This is probably due to bad media, but may be  
hardware-related. Residue information will normally be  
supplied.  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. The software should disable all further transactions to  
the drive and mark the drive as ‘bad.  
3. The software should tell the user that a serious fault  
has been detected with the drive and advise them to  
call their technical support.  
4. Log the incident in the system log.  
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Code Meaning  
Comments  
11 00 Unrecovered read error  
A read from tape has failed. This is probably due to bad  
media, but may be hardware-related.  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Send a console message that an unrecovered error on  
write has occurred.  
3. Determine whether the error is deferred, and report  
the last successful operation and the failed operation  
to the calling application.  
4. Log the error and all recovery actions in the system  
log.  
Recovery action is as follows:  
1. Use Log Sense to find the age and state of the tape  
and the drive. Based on this, ask the user to clean the  
drive or replace the tape.  
2. If the fault is drive-related, ask the user to retry the  
operation after the drive has been cleaned.  
3. If the fault is with the media, prompt the user to back  
up the data to a new tape, restart the application and  
discard the current tape.  
11 12 Media Auxiliary Memory An error has occurred while attempting to write to MAM.  
read error  
The cartridge should not be used for further backups but  
should be able to be used for restoring data.  
14 00 Recorded entity not found A SPACE or LOCATE command failed because of the drive  
could not find the target of the operation because of a  
format violation.  
Action: 1. Terminate the I/O and return the appropriate error.  
2. Send a message to the console indicating that EOD  
could not be found because the tape has a corrupt  
format.  
3. Prompt the user to back up the data to another tape  
and discard the current one.  
4. Log the incident in the system log.  
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Code Meaning  
Comments  
14 03 End of data not found  
A read-type operation failed because a format violation  
related to a missing EOD data set, or there was an  
attempt to read a brand new tape.  
Action: 1. Terminate the I/O and return the appropriate error.  
2. Send a message to the console indicating that EOD  
could not be found because the tape has a corrupt  
format.  
3. Prompt the user to back up the data to another tape  
and discard the current one.  
4. Log the incident in the system log.  
30 00 Incompatible medium  
A write-type operation could not be executed because it  
is not supported on the tape type that is loaded.  
installed  
Action: 1. Terminate the I/O and return the appropriate error.  
2. Send a message to the console indicating that writing  
is not allowed on the type of tape that is currently  
loaded.  
3. Prompt the user to insert a different tape type.  
4. Log the incident in the system log.  
5. The calling application can retry the operation.  
30 01 Cannot read media,  
A LOCATE or SPACE command has found the tape is in a  
format not supported by the drive.  
unknown format  
Action: 1. Terminate the current I/O, and return the appropriate  
error.  
2. Send a message to the console indicating that the  
tape is in a format not supported by the drive.  
3. Prompt the user to eject the cartridge and insert a  
valid one.  
4. Log the incident in the system log.  
30 02 Cannot read media,  
A READ command could not be completed because the  
logical format is not correct.  
incompatible format  
Action: 1. Terminate the current I/O, and return the appropriate  
error.  
2. Send a message to the console indicating that the  
tape is wrongly formatted.  
3. Prompt the user to eject the cartridge and insert a  
valid one.  
4. Log the incident in the system log.  
30 04 Cannot write medium  
The tape’s Cartridge Memory is bad so that the tape is  
unusable.  
64 Sense keys and codes  
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Code Meaning  
Comments  
30 07 Cleaning failure  
A cleaning operation was attempted but could not be  
completed for some reason.  
Action: Use another cleaning cartridge because the current one  
has expired.  
30 0D WORMmedium—integrity The drive has detected an inconsistency when performing  
check failed  
an integrity check on a WORM cartridge. The cartridge  
may have been tampered with. Data can be read from  
the cartridge by setting the WTRE bit in the Device  
Configuration mode page. The event should be logged  
for audit purposes.  
Action: 1. Terminate the current I/O, and return the appropriate  
error.  
2. Send a message to the console indicating that the  
drive has detected an inconsistency in the WORM  
cartridge that indicates it may have been tampered  
with.  
3. Alert the user that the cartridge may have been  
tampered with.  
4. Log the incident in the system log for audit purposes.  
5. Initiate WTRE-controlled EOD with clear warnings to  
the end-user that the data may have been tampered  
with.  
31 00 Medium format corrupted READ or SPACE has tried to read data that is in a format  
that is recognized but which is not valid.  
Action: 1. Terminate the current I/O, and return the appropriate  
error.  
2. Send a message to the console indicating that there is  
a problem with the format of the tape in the drive.  
3. Prompt the user to eject the media and insert a valid  
Ultrium tape.  
4. Log the incident in the system log.  
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Code Meaning  
Comments  
3B 00 Sequential positioning  
The drive has failed to read data off tape. There are two  
possibilities:  
error  
The current command (such as READ, SPACE, REWIND,  
or WRITE) failed to complete successfully.  
The logical position has been lost.  
Action: 1. Attempt to recover by executing a REWIND command  
to return to a known position such as BOT.  
2. Space to the position of the last known successful  
command and retry the failing command.  
3. If this is unsuccessful, terminate the current I/O, and  
return the appropriate error.  
4. Prompt the user to back up the data to a new  
cartridge and discard the old one.  
5. Log the incident in the system log.  
50 00 Write append error  
A write-type command failed because the point at which  
to append data was unreadable. This was probably  
caused by a powerfail, or SCSI bus or Fibre Channel link  
reset, preventing the drive from completing a write  
operation properly and appending an EOD.  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Tell the user that the append point is unreadable  
3. Advise the user to back up the data to new media and  
reformat the failing tape.  
4. Log the incident in the system log.  
52 00 Cartridge fault  
A command could not be completed because of a fault  
with the tape cartridge.  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Tell the user that a serious fault has been detected  
with the tape cartridge.  
3. Advise the user to discard this cartridge and select a  
new one.  
4. Log the incident in the system log.  
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Code Meaning  
Comments  
53 00 Media load or eject failed A load or eject has failed.  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Inform the user that a serious fault has been detected  
with the tape cartridge.  
3. Advise the user to discard this cartridge and select a  
new one.  
4. Log the incident in the system log.  
53 04 Medium thread or  
The threading or unthreading operation failed.  
unthread failure  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Inform the user that a serious fault has been detected  
with the tape cartridge.  
3. Advise the user to discard this cartridge and select a  
new one.  
4. Log the incident in the system log.  
4h—HW ERROR  
The following actions apply to most additional sense codes for HW ERROR sense key:  
Action: 1. Terminate the current I/O and return the appropriate error.  
2. The software should disable all further transactions to the drive and mark the  
drive as ‘bad.  
3. The software should tell the user that a serious fault has been detected with the  
drive and advise them to call their technical support.  
4. Log the incident in the system log.  
Code Meaning  
Comments  
40 XX Diagnostic failure on  
A self-test command has detected an error, or a  
command is prohibited from execution due to failure of a  
previous diagnostic. “XX” is a vendor-specific code  
indicating the failing component.  
component XX  
Action: see above  
44 00 Internal target failure  
an “impossible” situation.  
Action: see above  
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Code Meaning  
Comments  
53 01 Unload tape failure  
The tape unload failed because it cannot be physically  
completed at this point in time.  
Action: see above  
82 83 Bad microcode detected  
The data transferred to the drive during a firmware  
upgrade is corrupt or incompatible with the drive  
hardware.  
Action: see above  
5h—ILLEGAL REQUEST  
The following actions apply to all additional sense codes in this group:  
Action: 1. Terminate the current I/O and return the appropriate error.  
2. Log the incident in the system log.  
3. Print out all the REQUEST SENSE data bytes and check bytes 15 through 17 to  
identify the location of the offending bits or bytes.  
4. Refer to the table of Drive Error Codes in Volume 3, SCSI Interface, of the  
Ultrium Technical Reference Manual to understand why the current values were  
rejected.  
5. This is likely to be an application fault. Send a message to the console “Illegal  
SCSI request to tape drive.  
Code Meaning  
Comments  
1A 00 Parameter list length error A MODE SELECT parameter list sent to the drive contains  
one of the following:  
An incomplete Mode Parameter header (must be  
4 bytes)  
An incomplete Mode Block Descriptor (must be 0 or  
8 bytes)  
An incomplete Mode page  
20 00 Invalid command opcode The drive does not recognize the opcode of the  
command it has received.  
24 00 Invalid field in CDB  
The drive has detected an invalid field in a command  
descriptor block.  
25 00 LUN not supported  
The command was addressed to a logical unit number  
that does not exist.  
26 00 Invalid field in parameter  
The drive detected an invalid field among the command  
parameters sent during the data phase.  
list  
26 01 Parameter not supported  
A request for an invalid page number has been sent.  
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Code Meaning  
Comments  
26 04 Invalid release of persistent The Persistent Reservation holder has tried to release the  
reservation  
persistent reservation using the PERSISTENT RESERVE OUT  
command, but the Scope or Type supplied was invalid.  
2C 00 Command sequence  
The sequence of SCSI commands is invalid.  
invalid  
Example 1: The use of the echo buffer was invalid. A  
WRITE BUFFER command is necessary before a READ  
BUFFER command.  
Example 2: Another initiator has already started a  
firmware download process.  
2C 0B Not reserved  
If the “Only If Reserved” bit is set in the Device  
Configuration Mode page, and the drive does not hold a  
(persistent) reservation, some commands will not be  
allowed to execute. In other words, some commands can  
only be executed if the drive is reserved.  
3B 0C Position past BOM  
A SET CAPACITY command was received when the  
logical position was not BOT, a necessary condition for  
this command.  
53 02 Medium removal prevented An unload operation failed to eject the tape because  
medium removal has been prevented.  
55 03 Insufficient resources  
A buffer has reached its full capacity.  
55 04 Insufficient registration  
FC interface only: There is only space for requests from  
32 initiators to register, using PERSISTENT RESERVE OUT  
commands.  
resources  
55 06 Media Auxiliary Memory There is insufficient space in the Host Attribute area in  
full  
MAM to fit the attribute that need to be written.  
Action: Check MAM attribute 0004h (MAM Space Remaining)  
to identify how much space remains in MAM.  
6h—UNIT ATTENTION  
Code Meaning  
Comments  
28 00 Not ready to ready  
A tape has been loaded successfully into the drive and is  
now ready to be accessed.  
transition  
Action: 1. The host should be polling, receiving a CHECK  
CONDITION with sense key 2h (NOT READY) and  
becoming ready), and expecting this transition.  
2. Send the console message: “Tape drive in process of  
becoming ready.  
3. After the transition, send the console message “Tape  
loaded - media may have changed.  
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Code Meaning  
Comments  
29 01 Power-on reset  
The drive has powered on since the host last accessed it.  
Action: 1. The action of the calling application depends on the  
current I/O and what the operating system is  
expecting.  
2. For parallel SCSI, the host should renegotiate transfer  
parameters, and reconfigure the drive with any  
host-specific operating parameters (burst size, bus  
activity limit, fixed or variable mode, and so on).  
3. The host should then report to the console that the  
drive has been reset.  
4. The I/O can be retried if desired.  
29 02 SCSI bus reset  
SCSI drives: The drive has received a SCSI reset signal  
since the host last accessed it.  
FC drives: The drive has received its first process login.  
The drive will be implicitly logged out after a Target  
Reset so this ASCQ will be posted after the host has  
performed port/process login.  
Action: As for 29 01h  
29 03 Bus device reset  
SCSI drives: The drive has received a SCSI bus device  
reset message since the host last accessed it.  
FC drives: The drive has received a process login when it  
was previously logged in for a particular host.  
Action: As for 29 01h  
29 04 Internal firmware reboot  
The drive has reset itself.  
Action: The host may renegotiate transfer parameters.  
29 05 Transceivers to SE  
SCSI drives only: The transceivers on the bus have been  
reset to Single-Ended.  
Action: As for 29 01h  
29 06 Transceivers to LVD  
SCSI drives only: The transceivers on the bus have been  
reset to LVD.  
Action: As for 29 01h  
29 07 I_T nexus loss occurred  
The drive has lost the connection with the initiator (host  
server).  
Action: The host may renegotiate transfer parameters.  
2A 01 Mode parameters changed The Mode parameters for the drive have been changed  
by a host other than the one issuing the command. UNIT  
ATTENTION is set for all hosts following a MODE SELECT  
command, apart from the host that issued the command.  
This code will only be returned in a multi-host  
environment.  
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Code Meaning  
Comments  
Action: When operating the drive in this type of environment, the  
following actions should occur:  
1. The calling application receiving this code should  
issue a MODE SENSE command requesting the drive  
to return all parameters.  
2. The application should check those parameters over  
which it has configuration control, to ensure that the  
current configuration of the drive does not conflict  
with what the application expects.  
3. If it finds discrepancies, the application can either  
reconfigure the drive to the original values, or halt  
and report an error.  
4. If an error is reported, a console message must be  
displayed, and information logged to the system log.  
2A 02 Log parameters changed  
The Log parameters for the drive have been changed by  
an initiator other than the one issuing the command.  
2A 03 Reservations pre-empted  
A PERSISTENT RESERVE OUT command with the Clear  
service action removed all reservations and the persistent  
reservation.  
2A 04 Reservations released  
A PERSISTENT RESERVE OUT command executed. The  
original persistent reservation has been replaced with  
another of a different type or removed completely.  
2A 05 Registrations pre-empted  
A PERSISTENT RESERVE OUT command was executed  
which removed all registrations.  
2A 11 Dataencryption parameters The encryption parameters that this initiator was using  
changed by another  
initiator  
have been modified by another initiator.  
2A 12 Dataencryption parameters The encryption parameters that this initiator was using  
changed by vendor specific have been modified because of a vendor specific event  
event  
(such as tape unload or reservation released).  
3F 01 Firmware upgraded  
The firmware in the drive has just been changed by a  
WRITE BUFFER or MAINTENANCE OUT command,  
Firmware Update Cartridge, ADI or ACI.  
3F 05 Device identifier changed A SET DEVICE IDENTIFIER command has been successful.  
3F 0E Reported LUNs data has  
changed  
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7h—DATA PROTECTION  
Code Meaning  
Comments  
26 10 Data decryption key fail limit A SECURITY PROTOCOL OUT command has failed because  
reached  
an incorrect key has been sent to the drive followed by a  
read, and this has happened ten times consecutively.  
Action: Further SECURITY PROTOCOL OUT commands will not  
succeed until one of these actions has been taken:  
Unload and reload the current tape.  
Power-cycle the drive.  
Advise the user that they are using the wrong key, or that  
there is a possible security attack.  
27 00 Write-protected  
This is set if a write operation (WRITE, WRITE FILEMARKS, or  
ERASE) is requested for a write-protected cartridge.  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Send a message to the console indicating that the drive  
has been trying to write to a write-protected tape.  
3. Subsequent action depends on the application.  
2A 13 Data encryption Key Instance The drive received a WRITE command from an initiator that  
Counter has changed  
had locked its encryption parameters to a specific Key  
Instance Counter, whose value has now changed.  
Action: 1. Issue SECURITY PROTOCOL IN command to find out what  
the current encryption parameters are.  
2. Issue a SECURITY PROTOCOL OUT command to set the  
correct security parameters.  
3. Notify the user of a possible system configuration issue,  
since several initiators are trying to control encryption  
parameters.  
30 00 Incompatible medium  
A write-type operation could not be executed because it is  
not supported on the tape type that is loaded.  
installed  
Action: 1. Terminate the I/O and return the appropriate error.  
2. Send a message to the console indicating that writing  
is not allowed on the type of tape that is currently  
loaded.  
3. Prompt the user to insert a different tape type.  
4. Log the incident in the system log.  
5. The calling application can retry the operation.  
30 05 Cannot write medium,  
For example, the drive tried to write to a tape of an  
incompatible generation.  
incompatible format  
72 Sense keys and codes  
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Code Meaning  
Comments  
30 0C WORM—overwrite attempted A write operation could not be executed because an  
overwrite has been attempted on a WORM cartridge. This  
may be because an overwrite backup was specified  
instead of an appended backup.  
Action: 1. Terminate the I/O and return the appropriate error.  
2. Send a message to the console indicating that an  
attempt has been made to overwrite on a WORM  
cartridge.  
3. Prompt the user to either use a new cartridge or change  
the operation to an appended backup.  
4. Log the incident in the system log.  
30 0D WORM—integrity check  
An attempt has been made to write to a WORM cartridge  
when the drive has detected inconsistencies while checking  
its integrity.  
failed  
Action: 1. Terminate the I/O and return the appropriate error.  
2. Send a message to the console indicating that the drive  
has detected an inconsistency with the WORM  
cartridge that indicates that it may have been tampered  
with.  
3. Advise the user that the tape may have been tampered  
with and they should use a different cartridge.  
4. Log the incident in the system log for audit purposes.  
74 00 Security error  
Generic security (encryption/decryption) error. For  
example, the Decryption mode is set to RAW and the drive  
has been asked to read, but the hardware does not allow  
this Decryption mode on the current block.  
74 01 Unable to decrypt data  
The drive encountered encrypted data while reading, but  
decryption mode is not enabled.  
Action: Send a SECURITY PROTOCOL OUT command with  
Decryption Mode set to Decrypt or Mixed, and the Key  
field specifying the correct decryption key.  
74 02 Unencrypted data  
The decryption mode is enabled but the drive encountered  
encountered while decrypting non-encrypted data while reading.  
Action: Send a SECURITY PROTOCOL OUT command with  
Decryption Mode set to Disable; alternatively with  
the correct decryption key.  
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Code Meaning  
Comments  
74 03 Incorrect data encryption key The drive read into a block of data which could not be  
decrypted with the current decryption key.  
Action: 1. Send a SECURITY PROTOCOL IN with the page set to  
Next Block Encryption Status to obtain information  
about the next block on tape.  
2. Send a SECURITY PROTOCOL OUT command with  
Decryption Mode set to Decrypt or Mixed, and the Key  
field specifying the correct decryption key  
74 04 Cryptographic integrity  
The next block failed the integrity validation process while  
the drive was attempting to read it.  
validation failed  
Action: Data may have been compromised, so the tape should not  
be trusted. Log the incident in the system log and notify the  
user.  
74 05 Key-associated data  
The Key-associated data descriptor values have changed  
compared to the values in the last recorded read.  
descriptors changed  
Action: None. The application may continue reading but it is  
advisable to send a SECURITY PROTOCOL IN command with  
the page set to Next Block Encryption Status to find out  
information about the next block on tape. The application  
may decide to change its own security parameters.  
8h—BLANK CHECK  
Code Meaning  
Comments  
00 05 End of Data (EOD)  
A READ or SPACE command terminated early because it  
encountered EOD.  
detected  
Action: 1. Terminate the current I/O and return the appropriate  
error to the calling application indicating that EOD  
has been encountered.  
2. Send a console message saying that EOD has been  
encountered.  
3. Recovery depends on the calling application and  
what was expected.  
74 Sense keys and codes  
HP restricted  
     
Code Meaning  
Comments  
14 03 End of Data not found  
A read-type operation failed because a format violation  
related to a missing EOD data set. The most likely cause  
is a tape with corrupt format (perhaps from a powerfail  
when the tape was being written).  
Action: 1. Terminate the current I/O and return the appropriate  
error.  
2. Send a message to the console indicating that EOD  
could not be found because the tape has corrupt  
format.  
3. Prompt the user to back up the data to another tape  
and discard the current one.  
4. Log the incident in the system log.  
Bh—ABORTED COMMAND  
The following action applies to all codes in this group:  
Action: 1. Terminate the current I/O and return the appropriate error.  
2. Log the incident in the system log.  
3. Send the console message “SCSI command aborted - low-level failure on SCSI  
bus” or for a Fibre Channel drive, “SCSI command aborted - low-level failure on  
Fibre Channel link.  
Code Meaning  
Comments  
3F 0F Echo buffer overwritten  
A READ BUFFER command has been received with Echo  
Buffer mode set, and the echo buffer has been  
overwritten by a different host from that which issued the  
READ BUFFER command.  
47 00 SCSI parity error  
The drive has detected a parity error, for example during  
Message phase or Data phase.  
47 01 Data phase CRC error  
For parallel SCSI only in non-Information Units mode, the  
drive has detected a CRC error during the data out  
phase.  
detected  
47 03 Information Unit CRC error For parallel SCSI only in Information Units mode, the  
detected  
drive has detected a CRC error during the command IU  
or data out phase.  
48 00 Initiator Detected Error  
asserted) was invalid.  
message received  
4B 00 Data phase error  
ACI received more raw data than expected.  
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Code Meaning  
Comments  
4E 00 Overlapped commands  
A host has selected the drive even though it already has  
a command outstanding.  
attempted  
74 08 Digital signature validation The SCSI command used to download the new firmware  
failure  
image failed because the firmware image digital  
signature could not be correctly validated.  
Dh—VOLUME OVERFLOW  
Code Meaning  
Comments  
00 02 End of Tape detected  
A WRITE or WRITE FILEMARKS command has encountered  
EOT or the physical end of tape. The EOM flag will be  
set.  
NOTE: When the sense, additional sense and qualifying sense keys are listed, the software may  
look at all three keys to determine action. The drive should use that exact combination to report that  
particular error.  
For example, a drive will report that it is not ready when there is no cartridge present by setting  
sense key = NOT READY with additional/qualifying sense keys = 04 02. No other combination of  
additional/qualifying sense keys may be used to report that particular condition.  
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7 Exception handling  
These pages cover methods of dealing with certain error conditions and exceptional circumstances.  
They include the following:  
A suggested Escalation Procedure to follow when exceptions occur  
How to make the most of the TapeAlert facility, see “Supporting TapeAlert” on page 78  
How to respond to the ‘Clean’ LED (lit on the front panel when there are an excessive number of  
retries or error corrections)  
The need for a pass-through mode, which can return information or commands specific to a  
vendor’s product  
How drives recover from read and write errors  
How to use the drive’s ability to read through media errors, so that as much data can be  
retrieved from a badly damaged tape as possible  
Typical escalation procedure  
For exception handling, there needs to be a well defined escalation path, through which the calling  
application, user, operator or System Supervisor may take increasingly drastic action to clear any  
product-related faults.  
An escalation procedure is important to allow local recovery where possible, and to avoid the  
unnecessary replacement of peripheral devices.  
A typical escalation procedure is as follows:  
1. Retrieve fault information.  
You can run HP’s Library and Tape Tools (L&TT) and obtain a ticket, or you can retrieve specific  
fault information from the following sources:  
• INQUIRY data, such as firmware revisions  
• REQUEST SENSE data, such as Additional Sense Codes and Drive Error Codes  
• MODE SENSE data, such as data on the current configuration  
• LOG SENSE data, stored in the drive’s logs  
2. Inform the user.  
The system gives the user helpful advice by attempting to decode the returned information, and  
also allows the user access to the raw data.  
3. Allow the user to try recovery.  
For any fault, the system allows the user to use simple recovery commands such as REWIND or  
LOAD/UNLOAD.  
4. Allow the user to reset devices.  
If these actions fail, including repeated attempts to retry the operation, the user should be able to  
reset devices on the SCSI bus selectively, through the use of a LOGICAL UNIT RESET Task  
Management function. This function is specific only to the device to which it is addressed and  
will not disturb other devices on the SCSI bus.  
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5. Parallel SCSI only: Allow the System Supervisor or support person to perform a controlled hard  
SCSI Bus Reset.  
If the LOGICAL UNIT RESET Task Management function fails to clear the problem, the System  
Supervisor or technical support person should be able to perform a controlled hard SCSI Bus  
Reset as follows:  
• Lock other users out cleanly.  
• Go to a minimal-system single-user mode.  
• Close all applications.  
• Execute a hard SCSI Bus Reset.  
The process should not require a complete shutdown and reboot of the system.  
Monitoring the condition of the drive and media  
Through TapeAlert, an HP LTO Ultrium tape drive constantly monitors the condition of the  
mechanism and media, and presents the results in a form that host software can readily use and  
users can easily understand.  
You can find a general description of TapeAlert in the diagnostics section of the User Guide.  
Supporting TapeAlert  
HP has refined the TapeAlert standard to include the Predictive Failure flag. If the drive sets this flag,  
the host should display a message that the drive is “about to fail and should be replaced. There  
should be no impact on ISV software if the TapeAlert standard is already fully supported.  
NOTE: Reading the TapeAlert log clears all the flags, as defined in the TapeAlert specification.  
The TapeAlert Log page consists of 64 flags that indicate potential problems with the drive, and that  
allow host software to suggest appropriate corrective action to the user. For example, if Flag 20  
(“Clean Now”) is set, the software should advise the user to clean the tape heads.  
The drive maintains both SSC and ADC TapeAlert flags because the two standards state different  
clearing conditions.  
The drive maintains separate copies of the SSC TapeAlert flags for each port. These are only  
cleared when a port retrieves its TapeAlert flags with a LOG SENSE command with page code  
2Eh, provided the TAPLSD (TapeAlert Prevent LOG SENSE Deactivation) mode parameter is zero  
in the Device Configuration Extension mode page.  
The drive also maintains a set of ADC TapeAlert flags, which are shared by each port. The ADC  
TapeAlert flags are not cleared when a port retrieves them with a LOG SENSE command with  
page code 12h.  
See Chapter 4 of Volume 3, SCSI Interface, of the HP Ultrium Technical Reference Guide for details  
of the TapeAlert log page.  
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Flags  
The following table lists the flags that could potentially be supported in tape drives. Of these, flags  
3,4,5,6,20,22 and 31 are mandatory for drives such as Ultrium drives that support cleaning  
cartridges.  
The flags are grouped into the following sections:  
Flags 1 to 19: For tape drive write/read management  
Flags 20 to 25: For cleaning management  
Flags 26 to 39: For tape drive hardware errors  
Flags 50 to 60: For additional tape drive errors  
For each flag, the message that the host software should display to the user is given, together with  
the cause of the flag being set. The Type column classifies the flags by seriousness into the following  
three groups:  
I Information A suggestion to the user.  
W Warning  
The user is advised to take action. Performance or data  
may be at risk otherwise.  
C Critical!  
Take action immediately.  
The Set column indicates if the flag can be set by LTO 4 drives. The other flags are supported but  
never set.  
Flag  
Type Set Recommended Host Message  
Cause  
Flags for Tape Drive Write/Read Management  
1 Read warning  
2 Write warning  
3 Hard error  
W
The tape drive is having problems  
The drive is having severe  
reading data. No data has been lost, trouble reading.  
but there has been a reduction in the  
capacity of the tape.  
W
The tape drive is having problems  
writing data. No data has been lost, trouble writing.  
but there has been a reduction in the  
capacity of the tape.  
The drive is having severe  
W The operation has stopped because This flag is set for any  
an error has occurred while reading unrecoverable  
or writing data which the drive  
cannot correct.  
read/write/positioning  
error, and is cleared  
internally when the tape is  
explanation of the error in  
conjunction with one of the  
recovery action flags 4, 5,  
or 6.  
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Flag  
Type Set Recommended Host Message  
Cause  
4 Media  
C
C
C
Your data is at risk:  
Media performance is  
severely degraded or the  
tape can no longer be  
written or read.  
1. Copy any data you require from  
this tape.  
2. Do not use this tape again.  
This flag is set for any  
unrecoverable  
read/write/positioningerror  
caused by faulty media. It is  
cleared internally when the  
media is ejected.  
3. Restart the operation with a  
different tape.  
5 Read failure  
The tape is damaged or the drive is The drive can no longer  
faulty. Call the tape supplier’s  
helpline.  
read data from the tape.  
The flag is set for any  
unrecoverable read error  
where the diagnosis is  
uncertain and could either  
be a faulty tape or faulty  
drive hardware. It is cleared  
internally when the tape is  
ejected.  
6 Write failure  
The tape is from a faulty batch or the The drive can no longer  
tape drive is faulty: write data to the tape.  
1. Use a good tape to test the drive. The flag is set for any  
unrecoverable  
2. If the problem persists, call the  
write/positioning error  
where the diagnosis is  
uncertain and could either  
be a faulty tape or faulty  
drive hardware. It is cleared  
internally when the tape is  
ejected.  
tape drive supplier’s helpline.  
7 Media life  
W
The tape cartridge has reached the The media has exceeded its  
end of its calculated useful life:  
specified life.  
1. Copy any data you need to  
another tape.  
2. Discard the old tape.  
8 Not data grade  
9 Write-protect  
W
C
Not relevant to Ultrium drives.  
You are trying to write to a  
A write command was  
attempted to a  
write-protected cartridge.  
write-protected tape.  
Remove the write-protection or use  
another tape.  
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Flag  
Type Set Recommended Host Message  
Cause  
10 No removal  
I
You cannot eject the cartridge  
A manual or software  
unload was attempted when  
Prevent Medium Removal  
was in force.  
because the tape drive is in use.  
Wait until the operation is complete  
before ejecting the cartridge.  
11 Cleaning media  
I
I
The tape in the drive is a cleaning  
A cleaning cartridge is  
loaded in the drive.  
cartridge.  
12 Unsupported  
You have tried to load a cartridge of Attempted load of an  
format  
a type that is not supported by this  
drive.  
unsupported tape format.  
13 Recoverable  
mechanical  
C
The operation has failed because the The tape has snapped or  
tape in the drive has experienced a suffered some other  
cartridge failure  
mechanical failure:  
mechanical failure in the  
drive, but the tape can still  
be ejected.  
1. Discard the old tape.  
2. Restart the operation with a  
different tape.  
14 Unrecoverable  
mechanical  
C
The operation has failed because the The tape has snapped or  
tape in the drive has experienced a suffered some other  
cartridge failure  
mechanical failure:  
mechanical failure in the  
drive and the tape cannot  
be ejected.  
1. Do not attempt to extract the tape  
cartridge.  
2. Call the tape drive supplier’s  
helpline.  
15 Memory chip in W The memory in the tape cartridge has The LTO-CM chip has failed  
cartridge failure  
failed, which reduces performance. in cartridge.  
Do not use the cartridge for further  
write operations.  
16 Forced eject  
C
C
The operation has failed because the A manual or forced eject  
tape cartridge was manually  
occurred while the drive was  
de-mounted while the tape drive was writing or reading.  
actively writing or reading.  
17 Read-only  
You have loaded a cartridge of a  
type that is read-only in this drive.  
The cartridge will appear as  
write-protected.  
A write command has been  
format  
attempted to a tape whose  
format is read-only in this  
drive.  
18 Tape directory  
corrupted on  
load  
W The tape directory on the cartridge The drive was powered  
performance will be degraded. The a permanent error prevented  
tape directory can be rebuilt by the tape directory being  
reading all the data on the cartridge. updated.  
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Flag  
Type Set Recommended Host Message  
Cause  
19 Nearing media  
I
The tape cartridge is nearing the end The tape may have  
life  
of its calculated life. It is  
recommended that you:  
exceeded its specified  
number of passes.  
1. Use another tape cartridge for  
your next backup.  
2. Store this tape cartridge in a safe  
place in case you need to restore  
data from it.  
Flags for Cleaning Management  
20 Clean now  
C
The tape drive needs cleaning:  
The tape drive has detected  
that it needs cleaning. The  
flag is cleared internally  
when the drive is cleaned  
If the operation has stopped, eject  
the tape and clean the drive.  
If the operation has not stopped, successfully.  
wait for it to finish and then clean  
the drive.  
Check the tape drive user’s  
manual for cleaning instructions.  
21 Clean periodic  
W
The tape drive is due for routine  
cleaning:  
The drive is ready for a  
periodic cleaning.  
1. Wait for the current operation to  
finish.  
2. Use a cleaning cartridge.  
3. Check the tape drive user’s  
manual for cleaning instructions.  
22 Expired  
C
The last cleaning cartridge used in  
The cleaning tape has  
expired.  
cleaning media  
the tape drive has worn out:  
1. Discard the worn-out cleaning  
The flag is set when the tape  
drive detects a cleaning  
cartridge.  
cycle was attempted but was  
not successful. It is cleared  
internally when the next  
2. Wait for the current operation to  
finish.  
3. Use a new cleaning cartridge.  
cleaning cycle is attempted.  
23 Invalid cleaning  
C
The last cleaning cartridge used in  
An invalid cleaning tape  
type was used.  
cartridge  
the tape drive was an invalid type:  
1. Do not use this cleaning cartridge  
in this drive.  
2. Wait for the current operation to  
finish.  
3. Use a valid cleaning cartridge.  
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Flag  
Type Set Recommended Host Message  
Cause  
24 Retension  
W
The tape drive has requested a  
retension operation.  
The drive is having trouble  
reading or writing that will  
be resolved by a retension  
cycle.  
requested  
25 Dual-port  
W
A redundant interface port on the  
tape drive has failed.  
One of the interface ports in  
a dual-port configuration (in  
other words, Fibre Channel)  
has failed.  
interface error  
Flags for Tape Drive Hardware Errors  
26 Cooling fan  
W
A tape drive cooling fan has failed. A fan inside the drive  
failure  
mechanism or enclosure has  
failed.  
27 Power supply  
W
A redundant power supply has failed A redundant PSU has failed  
failure  
inside the tape drive enclosure.  
Check the enclosure user’s manual  
for instructions on replacing the  
failed power supply.  
inside the tape drive  
enclosure or rack subsystem.  
28 Power  
W
W
The tape drive power consumption is The tape drive power  
consumption  
outside the specified range.  
consumption is outside the  
specified range.  
29 Drive  
Preventive maintenance of the tape The drive requires preventive  
maintenance  
drive is required.  
maintenance (not cleaning).  
Check the tape drive user’s manual  
for preventive maintenance tasks or  
call the tape drive supplier’s helpline.  
30 Hardware A  
C
C
The tape drive has a hardware fault: The drive has a hardware  
fault from which it can  
1. Eject the tape or magazine.  
2. Reset the drive.  
recover through a reset.  
3. Restart the operation.  
31 Hardware B  
The tape drive has a hardware fault: The drive has a hardware  
fault that is not read/write  
1. Turn the tape drive off and then  
related or that it can recover  
on again.  
from through a power cycle.  
2. Restart the operation.  
The flag is set when the tape  
3. If the problem persists, call the  
drive fails its internal  
cleared internally until the  
drive is powered off.  
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Flag  
Type Set Recommended Host Message  
Cause  
32 Interface  
W
The tape drive has a problem with  
the application client interface:  
The drive has identified an  
interface fault.  
1. Check the cables and cable  
connections.  
2. Restart the operation.  
33 Eject media  
C
The operation has failed:  
Error recovery action.  
1. Eject the tape or magazine.  
2. Insert the tape or magazine  
again.  
3. Restart the operation.  
34 Download fail  
W The firmware download has failed  
because you have tried to use the  
Firmware download failed.  
incorrect firmware for this tape drive.  
Obtain the correct firmware and try  
again.  
35 Drive humidity  
W
Environmental conditions inside the The drive’s humidity limits  
tape drive are outside the specified have been exceeded.  
humidity range.  
36 Drive  
W Environmental conditions inside the The drive is experiencing a  
tape drive are outside the specified cooling problem.  
temperature range.  
temperature  
37 Drive voltage  
W
The voltage supply to the tape drive Drive voltage limits have  
is outside the specified range.  
been exceeded.  
38 Predictive failure C  
A hardware failure of the drive is  
predicted. Call the tape drive  
supplier ‘s helpline.  
Failure of the drive’s  
hardware is predicted.  
39 Diagnostics  
W
The tape drive may have a hardware The drive may have a  
required  
fault. Run extended diagnostics to  
verify and diagnose the problem.  
hardware fault that may be  
identified by extended  
diagnostics (using a SEND  
DIAGNOSTIC command).  
Check the tape drive user’s manual  
for instructions on running extended  
diagnostic tests.  
Flags for Additional Tape Drive Errors  
Flags 40–49 are not currently used.  
50 Lost statistics  
W Media statistics have been lost at  
The drive or library has been  
powered on with a tape  
loaded.  
some time in the past.  
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Flag  
Type Set Recommended Host Message  
Cause  
51 Tape directory  
invalid at  
W The tape directory on the tape  
An error has occurred  
cartridge just unloaded has been  
preventing the tape directory  
unload  
corrupted. File search performance being updated on unload.  
will be degraded. The tape directory  
can be rebuilt by reading all the  
data.  
52 Tape system  
area write  
failure  
C
The tape just unloaded could not  
write its system area successfully:  
Write errors occurred while  
writing the system area on  
unload.  
1. Copy the data to another tape  
cartridge.  
2. Discard the old cartridge.  
53 Tape system  
area read  
failure  
C
C
The tape system area could not be  
read successfully at load time.  
Read errors occurred while  
reading the system area on  
load.  
Copy the data to another tape  
cartridge.  
The start of data could not be found The tape has been  
on the tape:  
54 No start of data  
damaged, bulk erased, or is  
of an incorrect format.  
1. Check that you are using the  
correct format tape.  
2. Discard the tape or return the  
tape to your supplier.  
55 Loading failure  
C
C
The operation has failed because the The drive is unable to load  
media cannot be loaded and  
threaded.  
the cassette and thread the  
tape.  
1. Remove the cartridge, inspect it  
as specified in the product  
manual, and retry the operation.  
2. If the problem persists, call the  
tape drive supplier’s help line.  
56 Unrecoverable  
The operation has failed because the The drive is unable to  
load failure  
tape cannot be unloaded:  
unload the tape.  
1. Do not attempt to extract the tape  
cartridge.  
2. Call the tape driver supplier’s  
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Flag  
Type Set Recommended Host Message  
Cause  
57 Automation  
C
The tape drive has a problem with  
the automation interface:  
The drive has identified a  
fault in the automation  
interface.  
interface failure  
1. Check the power to the  
automation system.  
2. Check the cables and cable  
connections.  
3. Call the supplier’s helpline if the  
problem persists.  
58 Firmware failure W The tape drive has reset itself due to There is a firmware bug.  
a detected firmware fault. If the  
problem persists, call the supplier’s  
helpline.  
59 WORM  
medium—integr  
ity check failed  
W The tape drive has detected an  
inconsistency while checking the  
WORM tape for integrity. Someone  
may have tampered with the  
cartridge.  
Someone has tampered with  
the WORM tape.  
60 WORM  
W An attempt has been made to  
overwrite user data on a WORM  
tape:  
The application software  
does not recognize the tape  
as WORM.  
medium—  
overwrite  
attempted  
1. If you used a WORM tape  
inadvertently, replace it with a  
normal data tape.  
2. If you used a WORM tape  
intentionally, check that:  
the software application is  
compatible with the WORM tape  
format you are using.  
the cartridge is bar-coded  
correctly for WORM.  
Flags 61–64 are not currently used  
Note that often messages will not appear in isolation. For example, message 01h (“The tape  
drive is having problems reading data.”) is likely to appear with a message  
suggesting remedial action, such as message 04h (“You are advised to copy any  
data...”) or message 14h (Clean Now).  
Each flag is cleared to zero in the following circumstances:  
At power-on.  
When specified corrective action has been taken, such as using a cleaning cartridge.  
When the TapeAlert Log page is read.  
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NOTE: Once cleared, a flag cannot be set again until the specified clearing conditions are met.  
So, for example, if the cartridge in the drive is not of data grade, once flag 8 has been cleared, it  
cannot be set again until the cartridge has been removed.  
Designing software to use the TapeAlert log  
When writing software to take advantage of the ability of a drive to predict problems and actions  
that a user should take, it is important not to exclude drives that do not support this feature. For this  
reason, the application should first check whether the TapeAlert Log page is supported by the drive  
and then use one of two methods to access the information:  
Use the MODE SELECT Informational Exceptions mode page to enable “Check Condition” mode.  
This means that the tape drive reports CHECK CONDITION on the next SCSI command after one  
or more TapeAlert flags are set. When CHECK CONDITION is received, the host software should  
behave as follows:  
a. It issues a REQUEST SENSE command. Additional sense of 5D00h indicates that the CHECK  
CONDITION was caused by TapeAlert. This enables the software to distinguish CHECK  
CONDITIONs caused by actual errors and those resulting from a TapeAlert flag being set.  
b. The software reads the TapeAlert log page to discover which flags are set (even for CHECK  
CONDITIONs caused by actual errors).  
Note that when CHECK CONDITION results from TapeAlert, the command that reported the  
CHECK CONDITION is not in error and will have completed successfully. It follows that the  
software should not repeat the command.  
Read the TapeAlert log page using LOG SENSE at the following times:  
• Immediately after a SCSI CHECK CONDITION/REQUEST SENSE cycle.  
• At the end of each tape where a backup or restore spans multiple tapes. The host must read  
the TapeAlert log page before a tape is ejected.  
• At the end of a backup or restore.  
It is also advisable to poll the TapeAlert log page every 60 seconds while the tape drive is idle.  
Using “Check Condition” mode is recommended over polling because it guarantees that the  
software will be aware of any TapeAlert flag being set. It is theoretically possible that TapeAlert  
information could be missed when polling, though the higher the frequency of polling, the smaller  
the chance is.  
TapeAlert models  
SSC-3rev02 specifies three optional methods for an application to monitor activation of TapeAlert  
flags. LTO 4 drives support two of those models:  
Polling the TapeAlert log page (2Eh) or the TapeAlert Response log page (12h);  
Configuring the device server to establish an Informational Exception condition (via mode page  
1Ch) upon activation of one or more TapeAlert flags.  
These are described in more detail below.  
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In addition, the application can determine which TapeAlert flags are supported by the device server  
through the TapeAlert supported flags VPD page (B2h).  
TapeAlert polling usage model  
In this model, the application configures the device server by setting the TASER bit in the Device  
Configuration Extension mode page (10h) to one.  
The device server does not notify the application that a TapeAlert flag has changed. The application  
can read the TapeAlert log page or the TapeAlert Response log page at any time (for example,  
polling every x seconds) or upon certain relevant operations:  
Before loading a tape  
Immediately after detecting an unrecoverable error  
Before unloading a tape  
At the end of a data transfer  
TapeAlert informational exception usage model  
In this model, the application configures the device server by setting the TASER bit in the Device  
Configuration Extension mode page (10h) to zero, and in the Informational Exceptions mode page,  
by setting the DExcpt bit to zero and the TEST bit to zero.  
The device server notifies the application that a TapeAlert flag has been activated by reporting and  
informational exception condition on the next SCSI command, with additional sense of 5D00h  
(failure prediction threshold exceeded). If the device server has been configured to return descriptor  
format sense data, the current state of all TapeAlert flags appears in the Information sense data  
descriptor. If not, the drive returns fixed format sense data and the application should read one of  
the TapeAlert log pages to retrieve the state of the TapeAlert flags.  
For more information see SSC-3 rev 02, section 4.2.15.  
Reading the TapeAlert log  
Each time the TapeAlert log page is read, the application should follow this procedure:  
1. Read all 64 flags to discover which are set (there may be more than one).  
There may also be data associated with a set flag in the remainder of the flag byte, which  
should also be read.  
2. For each flag that is set, log the associated error message.  
3. Notify the user through the normal methods (such as broadcast, E-Mail, SNMP) by displaying  
the error message suggested in the table. Include the following:  
• Details to identify which drive the message refers to.  
• The software label of the tape cartridge when relevant.  
• The severity of the message (Information, Warning or Critical, with Critical the most severe).  
Where there are several flags set, list the messages in ascending order of severity.  
4. Apply any error message filters in the software to the TapeAlert errors. If several TapeAlert flags  
are set, they should if possible be presented to the user as a single event. For example, the error  
messages could be displayed together in a single message box.  
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5. Optionally, automate the recommended recovery actions if there are multiple tape drives or  
autoloaders present.  
For example, the application could perform a cleaning cycle in response to flags 20 (Clean  
Now) and 21 (Clean Periodic). It could perform a tape copy for flags 4 (Media performance  
degraded) and 7 (Media life expired), and then retire the suspect tape cartridge.  
This provides an opportunity for applications to add value to the TapeAlert capability of the  
drives.  
NOTE: An application must not fail a backup job as a result of TapeAlert information. It should use  
the information as a preventative measure, taking action to avoid failure, or encouraging the user to  
take action. It should also retain the log information to help in diagnosis if a job does eventually fail.  
One-Button Disaster Recovery (OBDR)  
NOTE: FC drives and drives in libraries do not support OBDR.  
All HP Ultrium parallel-SCSI products support HP’s One-Button Disaster Recovery (OBDR)  
technology. This provides the fastest possible, one-step approach to regenerating a single server  
without using additional floppy disks or CD-ROMs.  
For a general overview, see “OBDR and CD-ROM Emulation” in Chapter 1, “Ultrium Features, of  
Background to Ultrium Drives, Volume 6 of the HP Ultrium Technical Manual. For details of the SCSI  
implementation, see “CD-ROM Emulation” in Chapter 1, “Interface Implementation, of SCSI  
Interface, Volume 3 of the HP Ultrium Technical Manual.  
For details of how to use OBDR see the appropriate User’s Guide.  
To identify whether the firmware supports OBDR, look for the string “$DR-10” in bytes 43–48 of  
the Inquiry data.  
Supporting OBDR  
The OBDR implementation in HP Ultrium drives is functionally identical to that in DAT/DDS, so no  
additional design or coding should be required in order to support it. The only effort needed should  
be in software testing.  
Responding to the ‘Clean’ LED  
potential tape or cleaning problems are flagged and corrected before the drive ever reaches the  
point of displaying the ‘Clean’ LED.  
If during normal operation, the drive detects an excessive number of RWW retries, the ‘Clean’ LED  
is lit. If this happens, a user should follow this procedure:  
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1. Clean the heads and try the operation again.  
2. If the ‘Clean’ LED is lit again, repeat the operation with another tape cartridge. If this clears the  
‘Clean’ LED, it indicates that the original cartridge is at fault. Copy the data from the cartridge  
onto a new one and discard the old cartridge.  
The ‘Clean’ LED is cleared by a cleaning cycle.  
Providing pass-through mode  
It is important for Drivers and Logical Device Managers to provide a pass-through mode that can  
return information or commands specific to a vendor’s product. The need for this is two-fold:  
Systems must support a great variety of new devices.  
All tape drives are similar to a degree; Drivers and Logical Device Managers tend to provide  
connectivity based on the assumption that 80% of all SCSI tape drives behave identically.  
Pass-through mode offers the following advantages:  
Peripheral manufacturer can provide value-added diagnostics and support applications over  
and above those that may be shipped with a system or application.  
System supervisors and operators can take advantage of specific product features otherwise  
excluded because the driver or manager only caters for 80% of SCSI drives.  
Technical support people have access to low-level device-specific information likely to be  
unavailable otherwise.  
Requirements for drivers and logical device managers  
Drivers and Logical Device Managers must allow the user to do the following:  
1. Create either a 6-byte, 10-byte, 12-byte or 16-byte SCSI Command Descriptor Block.  
2. Allocate a write buffer or file for any data associated with the SCSI command that will be sent to  
the drive.  
or  
Allocate a read buffer or file for any data associated with the SCSI command that will be  
returned by the drive.  
3. Link the command and data buffers.  
4. Launch the command.  
5. The driver should use its standard CHECK CONDITION and REQUEST SENSE routines to report  
whether the command completed successfully or not. The caller must have access to the raw  
REQUEST SENSE data.  
6. View any returned data.  
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Glossary  
ANSI  
American National Standards Institute, which sets standards for, amongst other things,  
SCSI and the safety of electrical devices.  
BOM  
Beginning Of Media. The first point on the tape that can be accessed by the drive.  
buffered mode  
A mode of data transfer in write operations that facilitates tape streaming. It is selected  
by setting the Buffered Mode Field to 1 or 2 in the SCSI MODE SELECT Parameter List  
header.  
compression  
A procedure in which data is transformed by the removal of redundant information in  
order to reduce the number of bits required to represent the data.  
compression ratio  
A measure of how much compression has occurred, defined as the ratio of the amount  
of uncompressed data to the amount of compressed data into which it is transformed.  
The LTO-DC algorithm can typically achieve a compression ratio of between 2:1 and  
4:1 depending on the nature of the data.  
decompression  
ECMA  
A procedure in which the original data is generated from compressed data.  
European Computer Manufacturers Association. The European equivalent of ANSI.  
EOD  
End Of Data. An area that signifies the end of the valid data. If new data is written  
over a larger quantity of old data, it is possible for data to exist after EOD, but  
because it is after EOD, this old data is no longer valid.  
EOM  
End Of Media format. The last usable point on the tape.  
EW-EOM  
Early Warning End Of Media. A physical mark or a device-computed position on the  
tape that tells the drive that it is approaching EOM.  
filemark  
FRU  
A mark written by the host. It does not necessarily separate files; it is up to the host to  
assign a meaning to the mark.  
Field Replaceable Unit, an assembly or group of components that is replaced in its  
entirety by Service Engineers when it contains a fault.  
hard error  
host  
An uncorrectable data error.  
The host computer system acting as controller for the drive.  
The process in which the drive takes in an inserted cartridge and goes online.  
load  
LUN  
Logical Unit Number, by which different devices at a particular SCSI ID can be  
addressed individually. The drive has a fixed LUN of 0.  
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offline  
online  
The drive is offline if the tape is currently unloaded or not in the drive. The host has  
limited access, and cannot perform any commands that would cause tape motion. The  
host can, however, load a tape, if one is inserted, and can execute any diagnostic tests  
that do not require tape motion.  
The drive is online when a tape is loaded. The host has access to all command  
operations, including those that access the tape, set configurations and run diagnostic  
tests.  
RWW  
see read-while-write”  
read-while-write  
RWW improves data integrity by reading data immediately after it is written and  
writing the data again if an error is found.  
TapeAlert  
WORM  
A set of 64 flags is held in the TapeAlert log that indicate faults or predicted faults with  
the drive or the media. By reading this log, host software can inform the user of  
existing or impending conditions, and can, for example, advise the user to change the  
tape.  
Write Once, Read Many  
92  
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Index  
cartridges  
A
identifying types 19  
ACI 17, 35, 37  
irregular 46  
cleaning 49  
unreadable 47  
command set 38  
WORM 22  
Clean LED 89  
cleaning 49, 58, 90  
cleaning cartridges 47, 61  
cleaning tape heads 12  
commands, ACI 38  
resetting drives 50  
supporting 42  
ACI 4.3, new features 39  
additional sense codes 57  
ADI 35  
ANSI 10, 91  
autochangers 17  
Automation Control Interface see ACI  
controlling 51  
ratio 91  
controlling 11, 51  
data transfer size 11  
design goals 13  
Diagnostic logs 13  
diagnostics, failure 67  
documents, related 7  
B
backup applications 11  
backward compatibility 39  
barcode support, WORM 25  
block mode  
fixed-length 11  
variable-length 11  
block size, maximum 28  
BOM 91  
buffer  
detecting speed 27  
displaying information 13  
maximizing use 11  
size at EW-EOM 51  
buffered mode 91  
C
capacity  
of tape 20  
E
remaining 20  
eject, failed 67  
encryption support 41  
EOD 91  
using SET CAPACITY 21  
Cartridge Memory 12, 20  
responding to tape data 25  
cartridge memory 19, 35  
unreadable 48  
detected 74  
not found 64, 75  
using instead of headers 28  
HP LTO Ultrium 4 drives technical reference manual, volume 2: software integration  
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93  
 
EOM 58, 62, 91  
EOPD 22  
EOT 76  
errors  
count 25  
hard 91  
failed 67  
parity 75  
read 63  
write 62, 66  
EW-EOM 91  
exception handling 77  
Diagnostic 13  
performance 28  
supporting 29  
F
Tape Capacity 20  
TapeAlert 13, 25, 78, 92  
LUNs 91  
faults, predicting 13, 78  
filemarks 91  
detected 58  
use of 32  
not ready 59  
support for additional 17  
firmware revision 13  
firmware upgrade 45, 48  
fixed-length block mode 11  
flags, TapeAlert 79  
format, corrupt 65  
FRU 91  
MAM  
full 69  
write error 63  
media labels 23  
memory, cartridge 19  
fixed-length block 11  
pass-through 90  
variable-length block 11  
monitoring condition 13, 78  
G
generation, finding 16  
H
hard error 91  
host 91  
I
identifying tape cartridge types 19  
INCITS 10  
non-immediate commands 11  
initialization 15  
INQUIRY command 13  
inquiry string recovery 15  
integrity of WORM media 24  
irregular cartridges 46  
ISO 10  
O
OBDR 89  
offline 92  
one-button disaster recovery 89  
online 92  
L
operating system drivers 15  
optimizing performance 11, 27  
LEDs, Clean 89  
LEDs, Use Cleaning Tape 89  
94  
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P
parity error 75  
TapeAlert  
partition size 52  
pass-through mode 38, 90  
drive-related 31  
informational exception usage model 88  
TapeAlert log 13, 25, 78, 92  
reading 88  
format-related 32  
host-related 29  
performance log 28  
polling frequency, Get Drive Status 45  
power-up sequence 43  
problems, predicting 13, 78  
product ID 15  
using 87  
capacity 20  
cleaning cartridge 61  
faulty 66  
R
identifying 28  
identifying types 19  
monitoring use 12  
status 20  
read errors 63  
reading the TapeAlert log 88  
remaining capacity 20  
reserved fields 43  
reset 50  
use of 12  
using 19  
WORM 22  
revision level 15, 16  
RWW 92  
tests, read/write 13  
time-out values 28  
transfer size 11, 27  
effect on performance 32  
troubleshooting 13  
retries 89  
retry counts 26  
S
SCSI pass-through mode 38  
sense keys  
ABORTED COMMAND 56, 75  
BLANK CHECK 56, 74  
DATA PROTECTION 56, 72  
HW ERROR 55, 67  
supporting features 35  
upgrading firmware 45  
ILLEGAL REQUEST 55, 68  
MEDIUM ERROR 54, 62  
NO SENSE 53, 58  
NOT READY 54, 59  
RECOVERED ERROR 53, 59  
UNIT ATTENTION 55, 69  
VOLUME OVERFLOW 57, 76  
SET CAPACITY command 21  
slave to a library controller 37  
speed, detecting 27  
vendor ID 15  
Windows drivers 15  
WORM 92  
status of tape 20  
WORM media 22  
write errors 62, 66  
write-protect 72  
support for additional LUNs 17  
HP LTO Ultrium 4 drives technical reference manual, volume 2: software integration  
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95  
96  
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