HP Hewlett Packard Portable Media Storage AX696 96243 User Manual

HP StoreVirtual Storage Multi-Site  
Configuration Guide  
Abstract  
This guide contains detailed instructions for designing and implementing the Multi-Site SAN features of the LeftHand OS. The  
Multi-Site SAN features enable you to synchronously and automatically mirror data between geographic sites. Topics include  
designs for network configurations and instructions about implementing the network designs. The intended audience is system  
administrators who manage HP StoreVirtual Storage solutions.  
For the latest version of this guide, see the HP website http://www.hp.com/support/StoreVirtualManuals.  
HP Part Number: AX696-96243  
Published: March 2013  
Edition: 7  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Contents  
Contents  
3
Download from Www.Somanuals.com. All Manuals Search And Download.  
4
Contents  
Download from Www.Somanuals.com. All Manuals Search And Download.  
1 Designing a Multi-Site SAN  
The HP StoreVirtual Multi-Site SAN features enable you to synchronously mirror data between sites  
automatically. You create a Multi-Site SAN by configuring equal numbers of storage systems into  
sites in the software.  
The Multi-Site SAN software enables the following features:  
Multi-Site clusters that can:  
Span up to three sites  
Span multiple subnets  
Have multiple VIPs  
Geographical awareness, enabled by designating storage systems as members of a particular  
site.  
Synchronously replicated (mirrored) data between sites, based on volume data protection  
level.  
Site information that ensures that data is mirrored between sites for high availability and  
disaster recovery.  
I/O path preferencing, so that application servers connect to storage systems located in the  
same site.  
Failover Manager support for automatic failover/failback in three-site configurations without  
requiring a physical storage system in the third site.  
Failover Manager for quorum management if the network connection between the two sites  
becomes unavailable. For information about the Failover Manager, see “Using the Failover  
Manager” in the HP StoreVirtual Storage User Guide.  
Failure protection through data replication, site design, and quorum managers. Multi-Site SAN  
can protect against data center failures (power or network outages or a natural disaster) and  
individual storage system failures (power or network outages, a system disaster, or a system  
component failure).  
Requirements  
All sites must have the same number of storage systems. Storage systems must be added to or  
removed from Multi-Site clusters in equal numbers.  
Designing the network for the Multi-Site SAN  
Good network design is a critical part of setting up a Multi-Site SAN that meets your needs. A  
good Multi-Site SAN network encompasses the following attributes:  
Reliability  
High availability  
High performance  
Best practices for implementing the Multi-Site SAN network  
Plan a single subnet for the Multi-Site SAN.  
Adequate bandwidth—Plan for 50 MB/sec of bandwidth for each storage system in each  
site. For instance, if each site contains five storage systems, then you need 250 MB/sec  
throughput. In this case, that translates into two Gigabit Ethernet links, or more.  
Designing the network for the Multi-Site SAN  
5
Download from Www.Somanuals.com. All Manuals Search And Download.  
           
Low round-trip latency—In order to not impact disk I/O to the application server, the round-trip  
latency between the sites must be no more than 2 ms.  
Redundant links—Have multiple physical connections (media) between the sites for redundancy.  
The network should be configured so that a link failure does not cause the Multi-Site SAN to  
go offline.  
Assign servers to sites—Avoid high-latency connections by assigning application servers to  
the site where the server is located. Application servers assigned to a site connect only to  
storage systems in the same site as follows:  
Without MPIO—With servers set up in the CMC with the load balancing option, the  
system sets up the iSCSI session only to storage systems assigned to the same site.  
With MPIO and the HP StoreVirtual DSM for Microsoft MPIO—The system sets up iSCSI  
sessions only to storage systems assigned to the same site.  
With MPIO and the Microsoft DSM—With servers set up in the CMC with the load  
balancing option, the system sets up the iSCSI session only to storage systems assigned  
to the same site.  
Use the Failover Manager—Unless you have storage systems in three physical sites, use a  
Failover Manager. Put the Failover Manager in the third site (physical or logical) located on  
a network that is isolated from the other sites and has a different power connection. Minimum  
requirement: 100 MBit/s with 5 MS latency. For information about the Failover Manager,  
see “Using the Failover Manager” in the HP StoreVirtual Storage User Guide.  
Common Multi-Site SAN network designs  
Based on the Multi-Site SAN configuration, there are many network designs that can be implemented  
that solve the redundancy, high availability, and performance requirements for the Multi-Site SAN.  
A few commonly used designs are:  
Dual redundant links between the sites  
Full-mesh triangular (three) redundant links between sites  
Hub and spoke central network core with redundant links out to each site  
Combination full-mesh core network with triangular (three) links between sites  
Balancing the requirements for high availability during certain types of failures in the Multi-Site  
SAN and the budget associated with the network infrastructure typically dictates the network  
architecture you choose to implement. The most redundant network typically will cost the most to  
implement. However, not implementing redundancy in the Multi-Site SAN network significantly  
curtails the benefits of the Multi-Site SAN software. Table 1 (page 6) shows the common Multi-Site  
network configurations and the types of failures against which they provide protection.  
Table 1 Common Multi-Site network configurations and failure protection of each  
Network topology  
Site failure protection  
Network failure protection Storage system failure  
protection  
Dual redundant links  
between sites  
Yes, with manual  
intervention  
Yes  
Yes  
Yes  
Yes  
Yes  
Full-mesh triangular links  
between sites  
Yes  
Yes  
Hub and spoke central core Yes  
Yes, so long as the core  
does not fail  
Combo full-mesh core with Yes  
triangular links between sites  
Yes  
6
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
         
Sample recommended network configurations for Multi-Site SANs  
This section provides illustrations of common network configurations for the topologies described  
in Table 1 (page 6). The clusters and sites can have many more storage systems than are depicted  
in these illustrations, which focus on the network design.  
Figure 1 Dual redundant links between two sites  
1. Dual redundant GigE links  
Figure 2 Dual redundant links between two sites with Failover Manager in logical third site  
1. Dual redundant GigE links  
2. Optional redundant path  
Designing the network for the Multi-Site SAN  
7
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Figure 3 Triangular network with Failover Manager  
1. Dual redundant GigE links  
Figure 4 Hub and spoke network core with redundant links out to each site  
1. Core network hub and spoke  
8
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Figure 5 Combination full-mesh core with triangular links to all sites  
1. Full mesh core network  
Using multiple subnets  
IMPORTANT: Best practice is to use a single subnet in most cases.  
You can use multiple subnets with a Multi-Site SAN. Multiple subnets let you have multiple VIPs,  
one VIP per subnet. The advantage of using multiple VIPs is that you can connect to a volume  
without having to leave the local subnet.  
Alternatively, you can assign an application server to a site. Application servers assigned to a site  
connect only to storage systems in the same site. For more information, see “Best practices for  
If you use multiple subnets within the iSCSI cluster and implement one subnet per site, you can take  
advantage of the following Multi-Site SAN features:  
One Virtual IP address per site. iSCSI discovery sessions are terminated on a storage system  
that is local to the application server in that site.  
Virtual IP addresses are hosted only on storage systems that reside in the same subnet as the  
VIP.  
Read and Write I/O requests are forwarded from the application server to a storage system  
that is in the same site as the server. This ensures that the I/O path is optimal and multiple  
network hops across the network link between the sites are eliminated.  
Figure 6 (page 10) shows an example of how the Multi-Site SAN setup maps to subnets, VIPs, and  
application servers.  
Designing the network for the Multi-Site SAN  
9
Download from Www.Somanuals.com. All Manuals Search And Download.  
     
Figure 6 Multi-Site SAN mapping to subnets, VIPs, and application servers  
1. Dual redundant GigE links  
Connecting volumes to multiple subnets in a Multi-Site SAN using the Microsoft iSCSI initiator  
Connecting to volumes in a multiple subnet configuration is similar to connecting to volumes in a  
single-site configuration, with the following important differences:  
You must configure all cluster VIPs for discovery, for proper failover/failback configuration of  
a Multi-Site SAN. List the VIPs in the preferred order of connection. For example, if Site A is  
the first preference for connection, put the VIP associated to Site A first in the discovery list.  
You must also log on to the volumes with the default Target Portal setting.  
Using multiple cluster VIPs when connecting to a Multi-Site SAN  
Use the Virtual IP address of the cluster when connecting to volumes. In a multiple subnet  
configuration, you must enter both of the VIPs of the multi-site cluster on all the application servers.  
In addition, all the application servers must have the VIPs listed in the same order. A sample  
Multi-Site SAN configuration is shown in Figure 7 (page 11). In this configuration, the cluster has  
three sites: Site A, Site B, and Site C. Site A is primary.  
Connecting application servers with single or multiple NICs to a Multi-Site SAN  
1. On each application server, enter the cluster VIPs in the same order as on the Discovery tab  
of the iSCSI Initiator Properties window.  
10  
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
         
Figure 7 Entering VIPs in a Multi-Site SAN configuration  
2. On the Targets tab, select the volume to log on to.  
3. Click Log On.  
4. Select the Enable multi-path check box if using MPIO.  
Figure 8 Logging on to volume  
5. [Optional] If you want this volume to be available after rebooting, select the Automatically  
restore... check box.  
6. Click Advanced to open the Advanced Settings window.  
7. Configure the Advanced Settings as follows:  
For Local adaptor, select Microsoft iSCSI initiator.  
For Source IP, select the IP address of the storage NIC to connect to the volume.  
For Target portal, leave as Default so that the Discovery list of VIPs is used in the same  
order on all storage systems.  
Designing the network for the Multi-Site SAN  
11  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Figure 9 Target portal value remains Default  
8. After setting the values, click OK to close the Advanced Settings dialog.  
9. Click OK again to finish logging on.  
10. If you want to set the MPIO load balancing policy, see the HP StoreVirtual Storage DSM for  
MPIO Deployment Guide.  
11. If you have multiple NICs, repeat steps 1 through 10 for the additional NICs.  
Using MPIO with multiple subnets  
When you are using multiple subnets in a Multi-Site SAN, the HP StoreVirtual DSM for Microsoft  
MPIO or Microsoft DSM will only build I/O paths to the storage systems that are in the same subnet  
as the application server. See the HP StoreVirtual Storage DSM for MPIO Deployment Guide for  
more information about MPIO.  
When using VMware ESX 4 or higher and its native MPIO in a Multi-Site SAN, you cannot configure  
more than one subnet and VIP. Multiple paths cannot be routed across subnets by the ESX/ESXi  
4 initiator. With VMware vSphere, the preferred configuration is a single subnet and with vCenter  
servers assigned to sites in LeftHand OS.  
Configuring sites and managers to achieve optimal high availability and  
redundancy  
Several recommended site configurations can be used with the Multi-Site SAN software. These  
configurations provide varying levels of availability and redundancy. Table 2 (page 13) shows  
the recommended configurations. Select the one that best matches your environment.  
12  
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
         
In addition to setting up the Multi-Site clusters for data replication, it is important to set up the SAN  
managers for quorum correctly to ensure that in the event of a failure the system can be properly  
recovered. Maintaining quorum can be either an automated process or manually recovered by an  
Administrator. Table 2 (page 13) summarizes common Multi-Site SAN and manager configurations.  
Table 2 Common configurations of Multi-Site SANs  
Number of sites  
Cluster/site setup  
Total number of  
managers of all types  
Failover Manager  
Site types  
Three physical sites  
Cluster spans two sites Min = three  
Max = five  
In the third site  
All sites are peer.  
Two physical sites,  
with logical third site  
Cluster spans two sites Min = three  
Max = five  
In the logical third site All sites are peer.  
Three physical sites  
Cluster spans three  
sites  
Min = three  
Max = five  
Not used  
Not used  
All sites are peer.  
Two physical sites  
Cluster spans two sites Min = three  
Max = five  
One site is designated  
primary.  
Best practice  
In a cluster that spans multiple sites, run the same number of managers in each site. In a cluster  
that spans two sites, run a Failover Manager in a third site (physical or logical) that is not included  
in the cluster (Figure 10 (page 13)). The one exception to this rule is the two-site configuration in  
which one site is configured as primary (Figure 13 (page 15)). In this case, run a majority of the  
managers in the primary site.  
Sample configurations  
The following diagrams illustrate the best practices for four different configurations.  
Figure 10 Three physical sites: cluster spans two sites, Failover Manager in third site  
1. Volumes are configured with Network RAID-10  
Configuring sites and managers to achieve optimal high availability and redundancy  
13  
Download from Www.Somanuals.com. All Manuals Search And Download.  
           
Figure 11 Two physical sites, logical third site: cluster spans two sites, Failover Manager in logical  
third site  
1. Volumes are configured with Network RAID-10  
Figure 12 Three physical sites: cluster spans three sites  
1. Volumes are configured with Network RAID-10+1  
14  
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Figure 13 Two physical sites: cluster spans two sites, one site is the primary site  
1. Volumes are configured with Network RAID-10  
Best practices for configuring quorum and managers in a Multi-Site SAN  
environment  
Configuring the appropriate number of managers in a Multi-Site SAN on the appropriate storage  
systems is an important part of setting up the Multi-Site SAN for high availability and fault tolerance.  
Table 3 (page 16) identifies common Multi-Site SAN configurations and the recommended manager  
configurations.  
Best practices for configuring quorum and managers in a Multi-Site SAN environment  
15  
Download from Www.Somanuals.com. All Manuals Search And Download.  
     
Table 3 Common Multi-Site SAN configurations with recommended managers  
Multi-Site SAN configuration  
Manager configuration  
Number of managers and number  
Needed to maintain quorum  
Two physical sites, one site is primary For four storage systems, run:  
Manager count = three  
Two managers in the primary site  
One manager in the secondary site  
Number for quorum = two  
Manager count = five  
For six storage systems or more, run:  
Number for quorum = three  
Three managers in the primary site  
Two managers in the secondary site  
Two physical sites, logical third site For two storage systems, run:  
Manager count = three  
One manager in each site  
Number for quorum = two  
One failover manager in the logical  
third site  
Manager count = five  
Number for quorum = three  
Two managers in each site, one  
failover manager in the logical third  
site  
For four storage systems or more, run:  
Two managers in each site  
One failover manager in the logical  
third site  
Three physical sites, cluster spans two For two storage systems, run:  
sites  
Manager count = three  
One manager in each site  
Number for quorum = two  
One failover manager in the third  
site  
Manager count = five  
Number for quorum = three  
For four storage systems, run:  
Two managers in each site  
One failover manager in the third  
site  
Three physical sites  
For three storage systems, run:  
One manager in each site  
For six or more storage systems, run:  
Manager count = three  
Number for quorum = two  
Manager count = five  
Three managers in the primary site  
Two managers in the secondary site  
Number for quorum = three  
Configuring data replication for optimal availability and redundancy  
The LeftHand OS software offers six levels of synchronous replication at a volume level. However,  
only three levels are appropriate for Multi-Site SAN configurations. Table 4 (page 17) describes  
the appropriate data replication levels for the Multi-Site SAN and associated supported  
configurations. To protect the data across sites, you must choose a data protection level with a  
number of mirrors that is at least equal to the number of sites in the configuration. For example, if  
the storage cluster spans three sites, then volumes must be configured as Network RAID–10+1 in  
order to ensure that data is the same on each site.  
NOTE: Network RAID-0, Network RAID-5, and Network RAID-6 do not tolerate site failures.  
16  
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
     
Table 4 Data protection levels and the supported number of sites  
Data protection level  
Network RAID-10  
Number of sites supported  
Two  
Network RAID–10+1  
Three  
NOTE: Two sites are supported, but not considered a  
best practice configuration.  
Network RAID–10+2  
Two  
NOTE: Three sites are supported, but are not considered  
a best practice configuration.  
Using Network RAID-10+2  
Using Network RAID-10+2 offers a level of data protection that enables the Multi-Site SAN to  
sustain a complete failure at one site and still maintain replicated data at the other site. For example,  
with Network RAID-10+2, there are four copies of data for the volume on the SAN. In a two-site  
configuration, the Multi-Site SAN software puts two of the four copies in one site and the remaining  
two in the other. If a site fails, the remaining site still has two copies and remains fault-tolerant.  
Setting up application clusters in a Multi-Site SAN environment  
Just as you can set up a Multi-Site SAN for data availability even when a complete site is offline,  
you can set up application clusters (Microsoft Cluster Server, VMware vSphere Cluster, Linux  
Cluster, and so forth) so that the cluster nodes are split between the sites. By having the automated  
failover/failback capabilities in the SAN, many application cluster technologies can leverage this  
capability to do “stretch” application clustering. Consult the application server-specific information  
for information about setting up clustering to support this type of failover. In general, you must  
perform three tasks:  
1. Set up an application server in each site.  
2. Assign the servers to the sites.  
3. Configure the application server to connect to the volumes on the SAN.  
4. If using multiple subnets in the storage cluster, log on to both VIPs in the cluster.  
If you are using the DSM for MPIO, see the HP StoreVirtual Storage DSM for MPIO Deployment  
Guide.  
Using the Primary Site designation in two-site configurations  
The Multi-Site SAN software supports designating a particular site as primary so that it does not  
go offline when the secondary site goes offline, or when the network link between sites goes offline.  
This is specific to the two-site configuration where, without this designation, there would be no way  
for the system to determine which site should remain online in the event of a network separation  
(classically known in the clustering/distributed systems world as a “split-brain” system).  
To set up this type of configuration:  
1. Designate one of the sites as primary.  
2. Start a majority of managers in the primary site.  
Contact HP Support for more information.  
Failure modes and recovery steps  
In general, there are three failure modes that a configuration like this can encounter that you should  
be aware of. Table 5 (page 18) summarizes the failure conditions and what you should do to  
rectify the issue.  
Setting up application clusters in a Multi-Site SAN environment  
17  
Download from Www.Somanuals.com. All Manuals Search And Download.  
             
Table 5 Failure conditions and resolutions  
Failure condition  
Resolution steps  
Secondary site offline  
Network link between sites fails  
Primary site offline  
None. The primary site will continue to operate.  
None. The primary site will continue to operate.  
1. If any of the storage systems running managers in the primary site  
can be brought back online, you should do this first.  
2. If all storage systems in the primary site are lost forever, you can use  
the Recover Quorum command-line function to recover quorum in the  
secondary site manually. For more information, see “Recover quorum  
operation,” next in this section  
Alternative setups  
The Multi-Site SAN software supports many other valid configurations than the four illustrated in  
the prior section. Table 6 (page 18) lists other possible configurations.  
Table 6 Alternative Multi-Site SAN configurations  
Alternate configuration  
Description  
Details  
More than one Multi-Site cluster in  
the management group  
Multiple clusters running within the The Multi-Site SAN software supports running  
same management group.  
many clusters in the same management  
group. You simply need to make sure that  
clusters have the same number of storage  
systems in each site for that particular cluster.  
More than three sites  
There are more than three sites in A particular cluster can only span up to three  
the cluster.  
sites. However, the Multi-Site SAN software  
supports having more than one cluster. The  
different clusters can span overlapping sites  
within the other clusters. In the example  
below, Cluster 1 and Cluster 2 are in the  
same management group, and between  
them they comprise four sites.  
Cluster 1  
Site 1  
Site 2  
Site 3  
Cluster 2  
Site 2  
Site 3  
Site 4  
Using Remote Copy with Multi-Site  
SAN  
The cluster contains Remote Copy, You can use Remote Copy to replicate data  
which like all other LeftHand OS from a Multi-Site SAN to a Disaster Recovery  
features, is compatible with  
Multi-Site SAN.  
or Backup site. See the chapter  
“Understanding and planning Remote Copy”  
in the HP StoreVirtual Storage Remote Copy  
User Guide.  
Multiple subnet clusters in the same The Multi-Site SAN features can be The Multi-Site SAN software can be used to  
site  
used to set up clusters that span  
create clusters that span multiple networks  
multiple subnets in the same site. (subnets) in larger Enterprise data centers.  
The storage systems can reside in the same  
or different sites. However, the cluster must  
18  
Designing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
       
Table 6 Alternative Multi-Site SAN configurations (continued)  
Alternate configuration  
Description  
Details  
be Multi-Site if it is to contain storage systems  
from different subnets.  
Using Virtual Manager  
The Virtual Manager capability  
The Virtual Manager is used in two-site  
remains in the product (a manual configurations, and is not as commonly used  
IMPORTANT: This is not a best  
practice.  
process for recovering quorum).  
as the Failover Manager. For more  
information about the Virtual Manager, see  
the chapter “Working with managers and  
quorum” in the HP StoreVirtual Storage User  
Guide.  
Alternative setups  
19  
Download from Www.Somanuals.com. All Manuals Search And Download.  
2 Implementing a Multi-Site SAN  
After you have designed the Multi-Site SAN configuration, you are ready to implement it.  
Before you begin  
Install Multi-Site SAN feature keys on the storage systems you are going to use.  
Register your storage systems. For more information, see “Registering advanced features” in the  
HP StoreVirtual Storage User Guide for information about registering your storage systems.  
Have the following information ready:  
The layout for storage systems and sites  
IP addresses, subnets, and VIPs to use for the Multi-Site cluster. You can use one VIP per subnet.  
(Optional) IP address and subnet for the Failover Manager  
Preparing to install a new Multi-Site SAN  
After you have finished planning the Multi-Site SAN and installed feature keys on the storage  
systems for the SAN, you are ready to begin installation.  
Preparing to convert an existing SAN to a Multi-Site SAN  
Converting an existing SAN to a Multi-Site SAN includes planning the site layout and network  
information along with the following considerations:  
Do you need to move/remove data from the existing SAN before reconfiguring it?  
Do you need to purchase additional storage systems to meet the requirement that each site  
have the same number of storage systems?  
Do you need to reconfigure your network to take advantage of the Multi-Site SAN capabilities?  
setting up your network appropriately.  
Installing the Multi-Site SAN  
To install a Multi-Site SAN, use the Management Groups, Clusters, and Volumes Wizard.  
20 Implementing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
               
Figure 14 Using the management group wizard to create a Multi-Site SAN  
NOTE: You must have at least one storage system for each site in the Available Systems pool  
before starting.  
Creating the management group  
The first part of the wizard creates the management group, which includes configuring the optimal  
number of managers for the initial setup. After you have the Multi-Site clusters configured, you  
need to review the manager configuration and adjust it according to the Multi-Site configuration  
you have planned. See “Configuring managers” (page 24).  
Creating Multi-Site clusters and volumes  
The path through the Multi-Site cluster portion of the wizard follows the steps listed below. The  
steps are described in greater detail in“Using the Multi-Site cluster wizard” (page 21).  
1. Create a cluster.  
2. Create a site and then assign storage systems to the site.  
3. Create the additional sites with storage systems, up to a total of three sites.  
4. Add one or more VIPs, depending on the number of subnets you have configured.  
5. Create volumes using the data protection levels dictated by your Multi-Site cluster design.  
Using the Multi-Site cluster wizard  
After creating the management group, the Create a Cluster window of the wizard is displayed.  
1. Select Multi-Site Cluster and then click Next.  
The Create Cluster window opens, displaying all of the storage systems you designated for  
the management group.  
2. Select all the storage systems targeted for all of the sites you plan to create, type a name for  
the cluster, and then click Next.  
Installing the Multi-Site SAN  
21  
Download from Www.Somanuals.com. All Manuals Search And Download.  
         
Creating sites  
When creating a new site, you first create the site and then assign storage systems to that site:  
1. Click New to open the New Site window.  
2. Enter a name for the site and an optional description.  
3. [Optional] Make the site primary, if appropriate.  
4. Click Add in the Site Systems section and then select the storage systems for this site.  
5. Click OK when you have finished creating the site.  
The Set up Sites window opens, displaying the first site created and the remaining unassigned  
storage systems in the list.  
6. Repeat these steps to create additional sites.  
7. When you have finished creating sites, click Next to continue with the wizard.  
If you want to assign servers to a site, you can edit the site to do so.  
8. Click Add to assign each VIP and Subnet Mask as planned for your site layout.  
NOTE: You can have one VIP per subnet.  
9. Click Next to continue.  
10. Click Finish when you have finished defining the volume.  
The management group, sites, Multi-Site cluster, and the volume are all created. This process  
takes some minutes.  
Viewing the Multi-Site cluster information  
You can view the completed sites and related information in two places. The Cluster tab view  
shows the sites in relation to the cluster.  
The Cluster tab view (Figure 15 (page 22)) which shows the sites.  
The Sites view (Figure 16 (page 23)) which shows detailed information about the storage  
systems in the cluster.  
Figure 15 Viewing the sites in the cluster Details tab  
22 Implementing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
     
Figure 16 Viewing the Sites Details tab window  
Converting an existing SAN to a Multi-Site SAN  
Plan the conversion according to the criteria described in “Preparing to convert an existing SAN  
Prerequisites  
Upgrade all storage systems to LeftHand OS software version 7.0 or later.  
Obtain the feature keys for storage systems to be used in the Multi-Site cluster.  
Apply the feature keys to the storage systems.  
Add or remove storage systems to the cluster if necessary to ensure you can have equal  
numbers of storage systems in each site. The wizard will not let you create sites with different  
numbers of storage systems; nor will it let you leave unassigned any storage systems currently  
in the cluster.  
Using the Multi-Site cluster wizard  
Use the Management Groups, Clusters, and Volumes wizard to convert an existing standard cluster  
to a Multi-Site cluster.  
1. Start the wizard from the Getting Started Launch Pad.  
2. In the wizard, select Existing Management Group and then click Next.  
3. Select the management group that contains the cluster you want to convert.  
4. Click Next to open the Create a Cluster window.  
5. Select Existing Cluster and Convert a Standard Cluster to a Multi-Site Cluster and then click  
Next.  
6. Click Next to select a specific cluster.  
7. Select the cluster you want to convert and then click Next.  
8. Follow the steps in “Creating sites” (page 22) to create the sites using the listed storage systems.  
9. After creating the sites, click Next The wizard opens the Assign Virtual IPs window.  
If the current cluster has a VIP assigned, it shows in this window. You can either use this VIP  
or assign new ones, according to the network plan for the Multi-Site cluster.  
Converting an existing SAN to a Multi-Site SAN 23  
Download from Www.Somanuals.com. All Manuals Search And Download.  
           
10. Assign one or more VIPs as planned for your site layout, and then click Next.  
The Create Volume window opens with the Skip Volume Creation box checked. If you want  
to create a new volume for your Multi-Site cluster, clear the box and fill in the volume  
information.  
11. Click Next to complete the wizard.  
12. Verify the settings for the sites you have just configured.  
13. Click Close when you finish reviewing the Summary information.  
If you want to assign servers to the site, you can edit the site to do so.  
14. Select the Sites node in the navigation window to view the new site configuration.  
Configuring managers  
After you have set up your management group, cluster, and sites, you may need to change the  
manager configuration of your Multi-Site SAN. You also need to add the Failover Manager in all  
but one type of configuration.  
Overview  
The LeftHand OS software automatically starts the regular manager on each storage system when  
creating a management group. The number of managers started depends on the number of storage  
systems in the group and whether you create a Multi-Site cluster. In some configurations, a Virtual  
Manager is also added to the management group. If, however, you plan to use a Failover Manager  
instead, you must manually install the Failover Manager on a separate server on the network and  
then add it to the management group as required by the design of your Multi-Site SAN. We  
recommend using the Failover Manager instead of the Virtual Manager because of its automated  
failover/failback capabilities.  
Configuring regular managers  
After you finish creating the management group, cluster, and sites for your Multi-Site SAN, review  
the manager configuration and change it as necessary. See “Common configurations of Multi-Site  
For information about management groups, managers, and starting and stopping managers, see  
the chapter “Working with management groups” in the HP StoreVirtual Storage User Guide.  
Fault tolerant manager configurations  
The LeftHand OS software tracks the configuration of managers to ensure that you have a  
fault-tolerant configuration. You may encounter messages with warnings or prerequisites you must  
meet before you can change the managers.  
For example, if you create a management group and a Multi-Site cluster using two or four storage  
systems, the management group has regular managers running on each storage system plus a  
Virtual Manager added to the management group. If you want to add a Failover Manager or stop  
a manager on one of the storage systems, you must first delete the Virtual Manager from the  
management group. Then you can make the other changes.  
Installing and configuring a Failover Manager  
If you are using a Multi-Site SAN configuration that calls for a Failover Manager, you must install  
the Failover Manager from the HP StoreVirtual VSA and Failover Manager DVD onto a separate  
server on the network. The Failover Manager can run on VMware ESX Server, VMware Server,  
VMware Player, or Microsoft Hyper-V Server. For detailed instructions for installing and configuring  
the Failover Manager see the section “Regular managers and specialized managers” in the HP  
StoreVirtual Storage User Guide.  
24 Implementing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
                 
Best practice  
Install the Failover Manager on a server in a separate physical location from the SAN sites, and  
then add it as a separate site in the management group. Doing so will prevent loss of quorum in  
a site failure, regardless of which single site fails.  
Adding the Failover Manager to the management group and site  
Adding the Failover Manager to the management group will likely cause the manager configuration  
to become less than optimal. Be sure to change the manager configuration to best reflect the new  
configuration of the management group. See the section “Best practice for managers in a  
management group” in the HP StoreVirtual Storage User Guide.  
1. Use Find to search for the Failover Manager, which appears in the Available Systems pool in  
the CMC.  
2. Right-click on the Failover Manager and then select Add to Existing Management Group.  
If there is more than one management group, select the correct one from the list that  
opens.  
If there is only one management group, the Failover Manager is added to the group.  
3. Select the Sites node in the navigation window.  
4. Right-click and then select New Site.  
5. In the New Site window, type the name and optional description for the Failover Manager  
site.  
6. Click Add in the Site Systems section.  
7. In the Add Systems to Sites window, select the Failover Manager from the list and then click  
OK.  
8. Click OK on the New Site window.  
The new Failover Manager site appears in the Sites Details tab.  
NOTE: You can also add the Failover Manager to an existing site.  
Configuring sites  
A site is a user-designated location in which storage systems are installed. Multi-Site SAN  
configurations have multiple sites with storage systems in each site. A site can be a logical  
configuration, such as a subnet within the same data center, department, or application. Volumes  
are replicated across sites, which ensures high availability and redundancy.  
You can also assign application servers to sites to avoid high-latency connections. Application  
servers assigned to a specific site connect only to storage systems in the same site.  
Sites have the following characteristics:  
Have equal numbers of storage systems, except for the Failover Manager, which can reside  
in a site by itself.  
Correlate to a geographical location and/or a configuration entity such as a subnet or power  
grid  
May be marked as primary  
Have a planned number of managers  
Have a planned data protection level  
Can have application servers assigned to them  
Configuring sites 25  
Download from Www.Somanuals.com. All Manuals Search And Download.  
         
Viewing sites in the CMC  
To view sites in the CMC, select the Sites node in the navigation window. The Sites node is displayed  
in every management group. Typically, however, the Sites Details tab shows the storage systems  
as unassigned. The site designation has no effect outside of the Multi-Site SAN configuration.  
Figure 17 No sites in a standard cluster  
When there is a Multi-Site cluster in the management group, the Sites Details tab shows the site  
assignments of the storage systems and servers.  
Figure 18 Site assignments in a Multi-Site cluster  
A management group can contain multiple clusters, some of which are Multi-Site and some of  
which are not. The Sites tab shows which clusters have sites and which do not (listed as Unassigned).  
Sites map view  
The Map View tab is useful for viewing the site assignments of the storage systems and servers.  
For more information on using the map view tools, see the HP StoreVirtual Storage User Guide.  
Sites map views include the following:  
26 Implementing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
       
Sites  
Sites (Grouped)  
Designating a primary site  
Use the Primary designation when you are using the Multi-Site cluster to maintain a primary site  
and a second site as a backup site. Designate the site as Primary when you create the site, or you  
can edit an existing site to make it primary. Only one site can be designated as Primary in a  
Multi-Site cluster. Make sure that the majority of managers are in the Primary site.  
Adding a site  
Create new sites directly in the CMC if you want to add a site to an existing cluster. You must have  
equal numbers of storage systems in each site. The Failover Manager can occupy a site by itself.  
1. Select the Sites node in the navigation window.  
2. Right-click and then select New Site.  
3. Type in a site name and optional description.  
4. (Optional) If you are setting up a primary configuration, select the Primary box.  
5. In the Site Systems section, click Add to add storage systems to the site.  
6. Select the appropriate systems, and click OK when you are finished.  
7. In the Site Servers section, click Add to add servers to the site.  
8. Select the servers, and click OK when you are finished.  
9. Click OK again when you have finished creating the new site.  
The Sites Details tab displays the new site with its storage systems and servers.  
Editing a site  
You can edit any aspect of the site, including:  
Changing the name and description of the site  
Changing the primary designation  
NOTE: Only one site can be primary.  
Adding or removing systems.  
IMPORTANT: All sites must have the same number of storage systems, except for the Failover  
Manager, which can reside in a site by itself.  
Adding or removing servers.  
To edit a site  
1. Right-click the Sites node in the navigation window and then select Edit Sites.  
2. Select the site you want to edit and then click Continue.  
3. Make the desired changes.  
4. Click OK when you are finished.  
Deleting a site  
You would delete a site from a Multi-Site cluster when you are either reconfiguring your SAN or  
recovering from a disaster or other failure.  
When only one site will be left in the cluster, deleting a site changes the cluster from a Multi-Site  
cluster to a standard cluster. If you then remove the storage system(s) assigned to that site, data  
that resides on the cluster will restripe.  
Configuring sites 27  
Download from Www.Somanuals.com. All Manuals Search And Download.  
                 
1. Select the Sites node in the navigation window.  
2. Select the site you want to delete in the Details tab, right-click, and then select Delete Site.  
NOTE: If only one site will be left in the cluster, the warning shown in “Deleting a site that  
Figure 19 Deleting a site that contains a storage system causes this warning  
3. Click OK to delete the site.  
Adding storage systems to a Multi-Site cluster  
After your Multi-Site cluster is configured and operating, you may want to add storage systems to  
the cluster for additional capacity or to create a new site. While you can add storage systems to  
the Multi-Site cluster at any time, you should add them in a way that does not violate the requirements  
of the Multi-Site SAN.  
See Adding a site” (page 27) if you plan to add the storage systems to a new site in the cluster.  
Adding additional capacity to existing sites  
Plan the following items according to your overall Multi-Site SAN configuration:  
Plan to add the same number of storage systems to each site.  
Obtain feature keys for the new storage systems.  
Plan the IP addresses and locations for the new storage systems to fit into the overall design  
for your Multi-Site SAN.  
To add capacity  
1. Add the license keys to the new storage systems.  
See “Registering Advanced Features” in the HP StoreVirtual Storage User Guide for more  
information about license keys.  
2. Add the new storage systems to the management group.  
3. Select the management group Sites node in the navigation window.  
4. Select the site to which you want to add a storage system.  
5. Right-click and then select Edit Site.  
6. In the Site Systems section, click Add to add the storage system.  
7. Select the storage system from the list and then click OK.  
8. Click OK to finish adding the storage system to the site.  
9. Repeat these steps for all the storage systems you are adding.  
10. Add the storage systems to the Multi-Site cluster, using the Edit Cluster window.  
28 Implementing a Multi-Site SAN  
Download from Www.Somanuals.com. All Manuals Search And Download.  
           
Removing storage systems from a Multi-Site cluster  
Removing storage systems from a Multi-Site cluster affects the capacity of the cluster and the  
Multi-Site configuration.  
Ensure that the capacity remaining after you remove the storage system(s) is sufficient for the  
data on the volumes.  
To maintain the Multi-Site configuration, plan to remove equal numbers of storage systems  
from each site.  
To remove the storage systems from the site  
1. Select the Sites node in the navigation window.  
2. Select the site from which you want to remove the storage system.  
3. Right-click and then select Edit Site.  
4. In the Site Systems section, select the storage system from the list and then click Remove.  
The storage system is removed from the list.  
5. Click OK on the Edit Site window.  
A message opens, warning that the Multi-Site cluster will change to a standard cluster if you  
remove the storage system.  
6. Click OK to continue.  
7. Repeat these steps to remove storage systems from additional sites.  
NOTE: Adding the Failover Manager will likely cause the manager configuration to become less  
than optimal. Be sure to change the manager configuration to best reflect the new configuration  
of the management group. See the section “Best practice for managers in a management group”  
in the HP StoreVirtual Storage User Guide.  
Removing servers from a site  
You can remove servers from a site as server use and needs change.  
To remove servers from a site:  
1. Select the Sites node in the navigation window.  
2. Select the site from which you want to remove the server.  
3. Right-click and then select Edit Site.  
4. In the Site Servers section, select the server from the list and then click Remove.  
The server is removed from the list.  
5. Click OK on the Edit Site window.  
A message opens, warning that the server will lose its site preference.  
6. Click OK to continue.  
Removing storage systems from a Multi-Site cluster 29  
Download from Www.Somanuals.com. All Manuals Search And Download.  
           
3 Support and other resources  
Contacting HP  
For worldwide technical support information, see the HP support website:  
Before contacting HP, collect the following information:  
Product model names and numbers  
Technical support registration number (if applicable)  
Product serial numbers  
Error messages  
Operating system type and revision level  
Detailed questions  
Subscription service  
HP recommends that you register your product at the Subscriber's Choice for Business website:  
After registering, you will receive e-mail notification of product enhancements, new driver versions,  
firmware updates, and other product resources.  
Rack stability  
Rack stability protects personnel and equipment.  
WARNING! To reduce the risk of personal injury or damage to equipment:  
Extend leveling jacks to the floor.  
Ensure that the full weight of the rack rests on the leveling jacks.  
Install stabilizing feet on the rack.  
In multiple-rack installations, fasten racks together securely.  
Extend only one rack component at a time. Racks can become unstable if more than one  
component is extended.  
Customer self repair  
HP customer self repair (CSR) programs allow you to repair your HP product. If a CSR part needs  
replacing, HP ships the part directly to you so that you can install it at your convenience. Some  
parts do not qualify for CSR. Your HP-authorized service provider will determine whether a repair  
can be accomplished by CSR.  
For more information about CSR, contact your local service provider, or see the CSR website:  
HP Insight Remote Support Software  
HP strongly recommends that you install HP Insight Remote Support software to complete the  
installation or upgrade of your product and to enable enhanced delivery of your HP Warranty,  
HP Care Pack Service or HP contractual support agreement. HP Insight Remote Support supplements  
your monitoring, 24x7 to ensure maximum system availability by providing intelligent event  
diagnosis, and automatic, secure submission of hardware event notifications to HP, which will  
30 Support and other resources  
Download from Www.Somanuals.com. All Manuals Search And Download.  
                     
initiate a fast and accurate resolution, based on your product’s service level. Notifications may be  
sent to your authorized HP Channel Partner for on-site service, if configured and available in your  
country. The software is available in two variants:  
HP Insight Remote Support Standard: This software supports server and storage devices and  
is optimized for environments with 1-50 servers. Ideal for customers who can benefit from  
proactive notification, but do not need proactive service delivery and integration with a  
management platform.  
HP Insight Remote Support Advanced: This software provides comprehensive remote monitoring  
and proactive service support for nearly all HP servers, storage, network, and SAN  
environments, plus selected non-HP servers that have a support obligation with HP. It is  
integrated with HP Systems Insight Manager. A dedicated server is recommended to host both  
HP Systems Insight Manager and HP Insight Remote Support Advanced.  
Details for both versions are available at: http://www.hp.com/go/insightremotesupport  
To download the software, go to Software Depot:  
Select Insight Remote Support from the menu on the right.  
Related information  
You can find the documents referenced in this guide from the Manuals page:  
HP websites  
For additional information, see the following HP websites:  
Related information  
31  
Download from Www.Somanuals.com. All Manuals Search And Download.  
       
4 Documentation feedback  
HP is committed to providing documentation that meets your needs. To help us improve the  
documentation, send any errors, suggestions, or comments to Documentation Feedback  
([email protected]). Include the document title and part number, version number, or the URL  
when submitting your feedback.  
32 Documentation feedback  
Download from Www.Somanuals.com. All Manuals Search And Download.  
   
Glossary  
The following glossary provides definitions of terms used in the LeftHand OS software  
and the HP StoreVirtual Storage.  
acting primary  
volume  
The remote volume, when it assumes the role of the primary volume in a failover scenario.  
Active-Passive  
A type of network bonding which, in the event of a NIC failure, causes the logical interface to  
use another NIC in the bond until the preferred NIC resumes operation. At that point, data transfer  
resumes on the preferred NIC.  
Adaptive Load  
Balancing  
A type of network bonding in which the logical interface performs load balancing of data  
transmission.  
application-managed snapshot  
Snapshot of a volume that is taken while the application that is serving that volume is quiesced.  
Because the application is quiesced, the data in the snapshot is consistent with the application's  
view of the data. That is, no data was in flight or cached waiting to be written.  
authentication  
group  
For release 7.0 and earlier, identifies the client or entity accessing the volume. Not used in release  
8.0 and later.  
Auto Discover  
A feature in the CMC that automatically searches for storage systems on the subnet the CMC is  
connected to. Any storage systems it discovers appear in the navigation window on the left side  
of the CMC.  
Bond0  
Interface created for network interface failover and only appears after configuring for failover.  
Combining physical network interfaces into a single logical interface.  
bonding  
boot device  
Compact flash cards from which the storage system boots up. Also known as disk-on-modules or  
DOMs.  
CHAP  
CLI  
Challenge-Handshake Authentication Protocol.  
Command-line interface. An interface comprised of various commands which are used to control  
operating system responses.  
clone point  
cluster  
The snapshot that has two or more volumes related to it. A clone point is created when a  
SmartClone volume is created from a snapshot or from snapshot temporary space.  
A cluster is a grouping of storage systems that create the storage pool from which you create  
volumes.  
CMC  
Centralized Management Console. See HP StoreVirtual Centralized Management Console.  
The unicast communication among storage systems and application servers.  
communication  
mode  
community string  
The community string acts as an authentication password. It identifies hosts that are allowed  
read-only access to the SNMP data.  
Configuration  
Summary  
The Configuration Summary displays an overview of the volumes, snapshots, storage systems,  
and iSCSI sessions in the HP StoreVirtual Storage. It provides an overview of the storage network  
broken out by management groups.  
data center  
Also known as a “Site.” A data center is a physical location in your environment where application  
servers, SAN storage and network equipment reside. In the LeftHand OS Multi-Site software, a  
data center is typically referred to as a site.  
disaster recovery  
site  
Similar to a secondary site, the disaster recovery site is used to operate the SAN in the event of  
a disaster.  
disk status  
Whether the disk is:  
Active - on and participating in RAID  
Uninitialized or Inactive - On but not participating in RAID  
Off or Missing - Not on  
DMA Off - disk unavailable due to faulty hardware or improperly seated in the chassis  
33  
Download from Www.Somanuals.com. All Manuals Search And Download.  
   
DSM  
Device Specific Module.  
DSM for MPIO  
The HP StoreVirtual DSM for Microsoft MPIO vendor-specific DSM that interfaces with the Microsoft  
MPIO framework.  
failback  
After failover, the process by which you restore the primary volume and turn the acting primary  
back into a remote volume.  
failover  
The process by which the user transfers operation of the application server over to the remote  
volume. This can be a manual operation, a scripted operation, or VMware enabled.  
Failover Manager  
A specialized manager running as a VMware appliance that allows you to place a quorum  
tie-breaker system into a 3rd location in the network to provide for automated failover/failback  
of the Multi-Site SAN clusters. The Failover Manager is designed to run on VMware ESX Server,  
VMware Server, and VMware Player. It is installed on hardware separate from the SAN hardware.  
failover recovery  
After failover, the process by which the user chooses to fail back to the primary volume or to  
make the acting primary into a permanent primary volume.  
frame size  
The frame size specifies the size of data packets that are transferred over the network.  
full provisioning  
Full provisioning reserves the same amount of space on the SAN as is presented to application  
servers.  
ghost storage  
system  
When using Repair Storage System, a “ghost” storage system acts as a placeholder in the cluster,  
keeping the cluster intact, while you repair or replace the storage system.  
Graphical Legend  
Describes all the icons used in the CMC:  
Items tab - displays the icons used to represent virtual items displayed in the CMC  
Hardware tab - displays the icons that represent the physical storage units.  
hardware reports  
hostname  
Hardware reports display point-in-time statistics about the performance and health of the storage  
system, its drives, and configuration.  
The hostname on a storage system is the user-definable name that displays below the storage  
system icon in the network window. It is also visible when the users browse the network.  
HP StoreVirtual  
Centralized  
Management  
Console  
management interface for the LeftHand OS software.  
ID LED  
iSCSI  
LED lights on the physical storage system so that you can find that system in a rack.  
Internet small computer system interface. Like an ordinary SCSI interface, iSCSI is standards-based  
and efficiently transmits block-level data between a host computer (such as a server that hosts  
Exchange or SQL Server) and a target device (such as the HP All-in-One Storage System). By  
carrying SCSI commands over IP networks, iSCSI is used to facilitate data transfers over intranets  
and to manage storage over long distances.  
iSCSI load  
balancing  
Improves iSCSI performance and scalability by distributing iSCSI sessions for different volumes  
evenly across storage systems in a cluster.  
LeftHand OS  
interface  
When you initially set up a storage system using the Configuration Interface, the first interface  
that you configure becomes the interface used for the LeftHand OS software communication.  
license key  
A WWN-encoded sequence that is obtained from the license key fulfillment website.  
Link Aggregation  
Dynamic Mode  
A type of network bonding in which the logical interface uses both NICs simultaneously for data  
transfer.  
log files  
Log files for the storage system are stored both locally on the storage system and are also written  
to a remote log server.  
logical site  
This site is on an isolated network and power connection than the other sites. However, it can  
be in the same physical location as one of the real sites. Also, a site for a Failover Manager.  
management  
group  
A collection of one or more storage systems which serves as the container within which you cluster  
storage systems and create volumes for storage.  
managers  
Manager software runs on storage systems within a management group. You start managers on  
designated storage systems to govern the activity of all of the storage systems in the group.  
34 Glossary  
Download from Www.Somanuals.com. All Manuals Search And Download.  
MIB  
Management information base. A database of managed objects accessed by network management  
protocols. An SNMP MIB is a set of parameters that an SNMP management station can query  
or set in the SNMP agent of a network device (for example, a router).  
Multi-Site cluster  
A cluster of storage that spans multiple sites (up to three). A Multi-Site cluster must meet at least  
one of the following conditions:  
Contain storage systems that reside in two or more sites  
Contain storage systems that span subnets  
Contain multiple VIPs. The cluster can have a single site, and the multiple VIPs make it a  
multi-site cluster.  
network RAID  
Synchronous replication, mirroring or parity protection on a volume-by-volume basis. Protecting  
data for a volume across all storage systems in the cluster. Network RAID-10, 10+1 or 10+2 is  
required to protect data in HP StoreVirtual Storage.  
network window  
NTP  
Graphically depicts the status of each storage system. Storage systems on the network are either  
available or part of a management group.  
Network Time Protocol  
original primary  
volume  
The primary volume that fails and then is returned to service.  
overprovisioned  
cluster  
An overprovisioned cluster occurs when the total provisioned space of all volumes and snapshots  
is greater than the physical space available on the cluster. This can occur when there are snapshot  
schedules and/or thinly provisioned volumes related to the cluster.  
parity  
In RAID 5, redundant information is stored as parity distributed across the disks. Parity allows the  
storage system to use more disk capacity for data storage.  
peer site  
Absence of a primary site designation makes all the sites peer sites.  
point-in-time  
snapshot  
Snapshots that are taken at a specific point in time, but an application writing to that volume may  
not be quiesced. Thus, data may be in flight or cached and the actual data on the volume may  
not be consistent with the application's view of the data.  
preferred interface A preferred interface is the interface within an active backup bond that is used for data transfer  
during normal operation.  
primary site  
A site designation assigned by the administrator in the HP StoreVirtual Centralized Management  
Console. A primary site is more important than a secondary site. In this setup, you would run a  
majority of managers in the primary site. In a two-site setup, this allows the primary site to stay  
online even if the network link between the primary and secondary sites fails. Typically, the  
primary site has majority/all of the application servers. In configurations that do not designate  
a primary site, the sites are referred to as “peer” sites.  
primary snapshot  
primary volume  
quorum  
A snapshot of the primary volume which is created in the process of creating a remote snapshot.  
The primary snapshot is located on the same cluster as the primary volume.  
The volume which is being accessed (read/write) by the application server. The primary volume  
is the volume that is backed up with Remote Copy.  
A majority of managers required to be running and communicating with each other in order for  
the LeftHand OS software to function.  
RAID device  
RAID (originally redundant array of inexpensive disks, now redundant array of independent disks)  
refers to a data storage scheme using multiple hard drives to share or replicate data among the  
drives.  
RAID levels  
Type of RAID configuration:  
RAID 0 - data striped across disk set  
RAID 1 - data mirrored from one disk onto a second disk  
RAID 10 - mirrored sets of RAID 1 disks  
RAID 5 - data blocks are distributed across all disks in a RAID set. Redundant information  
is stored as parity distributed across the disks.  
RAID quorum  
Number of intact disks required to maintain data integrity in a RAID set.  
35  
Download from Www.Somanuals.com. All Manuals Search And Download.  
RAID rebuild rate  
RAID status  
The rate at which the RAID configuration rebuilds if a disk is replaced.  
Condition of RAID on the storage system:  
Normal - RAID is synchronized and running. No action is required.  
Rebuild - A new disk has been inserted in a drive bay and RAID is currently rebuilding. No  
action is required.  
Degraded - RAID is not functioning properly. Either a disk needs to be replaced or a  
replacement disk has been inserted in a drive.  
Off - Data cannot be stored on the storage system. The storage system is offline and flashes  
red in the network window.  
register  
Register individual storage systems to use add-on applications. Registration requires sending in  
the storage system serial numbers to purchase the license keys, which are then applied to the  
storage system.  
remote copy pair  
remote snapshot  
The primary volume and its related remote volume.  
An identical copy of a primary snapshot. The remote snapshot is located on the same cluster as  
the remote volume.  
remote volume  
The volume that resides in the Remote Copy location where the remote snapshots are created.  
The remote volume contains no data. It acts as a pointer to tell the system where to make the  
copy of the primary snapshot. The remote volume can be stored in these ways:  
In the same cluster in the same management group  
In a different cluster in a different management group  
In a different cluster in the same management group  
Repair storage  
system  
Creates a placeholder in the cluster, in the form of a “ghost” storage system, that keeps the cluster  
intact while you remove the storage system to replace a disk or replace the storage system itself,  
and return it to the cluster.  
replication level  
In Release 8.5 this changes to data protection level. Prior to release 8.5, replication level is the  
term that designated how many copies of data to keep in the cluster.  
replication priority Removed in Release 8.5. Prior to Release 8.5, replication priority allowed you to designate  
whether data availability or redundancy is more important in your configuration. Release 8.5  
forward defaults to availability. This default can be changed using the HP StoreVirtual LeftHand  
OS Command Line Interface.  
restripe  
Striped data is stored across all disks in the cluster. You might change the configuration of a  
volume, for example, change data protection level, add a storage system, or remove a storage  
system. Because of your change, the pages in the volume must be reorganized across the new  
configuration. The system can keep track of several configuration changes at once. This means  
you can change configurations, even while a volume is in the midst of a different reconfiguration.  
In particular, if a reconfiguration was done by accident, you don't have to wait until it finishes  
to change back to the original configuration. See “Stripe.  
resync  
When a storage system goes down, and writes continue to a second storage system, and the  
original store comes back up, the original storage system needs to recoup the exact data captured  
by the second storage system.  
rolling back  
Replaces the original volume with a read/write copy of a selected snapshot. Starting with release  
8.0, the new volume retains the same name.  
secondary site  
A site that is less important than the primary site. In this setup a minority of managers runs in the  
secondary site. In a two-site setup, this allows the secondary site to go offline if the network link  
between the Primary and secondary sites fails. Typically, the secondary site has a minority, or  
none, of the application servers. If the primary site fails, customers can manually recover quorum  
in the secondary site.  
server  
An application server that you set up in a management group and then assign volumes to it to  
provide access to those volumes.  
shared snapshot  
Shared snapshots occur when a clone point is created from a newer snapshot that has older  
snapshots below it in the tree. All the volumes created from the clone point will display these  
older snapshots that they share, as well as the clone point.  
36 Glossary  
Download from Www.Somanuals.com. All Manuals Search And Download.  
site  
A user-designated location in which storage systems are installed. Multi-Site SAN configurations  
have multiple sites with storage systems in each site, and each site has its own subnet. A site can  
be a logical configuration, such as a subnet within the same data center, department, or  
application.  
SmartClone  
volume  
SmartClone volumes are space-efficient copies of existing volumes or snapshots. They appear as  
multiple volumes that share a common snapshot, called a clone point. They share this snapshot  
data on the SAN.  
snapshot set  
snapshot  
Application-managed snapshots created for a volume set.  
A fixed version of a volume for use with backup and other applications.  
Use traps to have an SNMP tool send alerts when a monitoring threshold is reached.  
HP StoreVirtual Application Integration Solution Pack  
SNMP traps  
solution pack  
split mirror  
A full copy of data that has been split off from the original and is no longer being updated.  
standard cluster  
Also known as a “cluster.” A standard cluster is one that does not use any of the Multi-Site features  
within the LeftHand OS software. Standard clusters:  
Cannot contain storage systems that are designated to reside in a site.  
Cannot contain storage systems that span subnets.  
Can only have a single VIP.  
storage server  
stripe  
Storage server software maintains the customer's data. It reads to and writes from disks in response  
to customer reads and writes of LeftHand OS volumes.  
Striped data is stored across all disks in the array, which increases performance but does not  
provide fault tolerance.  
synchronize  
The process of copying the most recent snapshot from the primary volume to a new remote  
snapshot. On failback, synchronization is the process of copying the most recent remote snapshot  
back to the primary volume. The CMC displays the progress of this synchronization. Also, you  
can manually synchronize if necessary to include data that is on the remote volume but not the  
primary.  
target secret  
Target secret is used in both 1-way and 2-way CHAP when the target (volume) challenges the  
iSCSI initiator.  
temporary space  
Temporary space is created when a snapshot is mounted for use by applications and operating  
systems that need to write to the snapshot when they access it. Temporary space can be converted  
to a volume using the SmartClone process.  
thin provisioning  
trap  
Thin provisioning reserves less space on the SAN than is presented to application servers.  
A type of SNMP message used to signal that an event has occurred. (SNIA)  
The Trap Community String is used for client-side authentication when using SNMP.  
Trap Community  
String  
unicast  
Communication between a single sender and a single receiver over a network.  
virtual IP address  
VIP  
virtual IP address  
A highly available address that ensures that if a storage system in a cluster becomes unavailable,  
servers can still access the volume through the other storage systems in the cluster.  
virtual machine  
virtual manager  
volume  
A virtual storage appliance that provides one or more simultaneous storage environments in which  
LeftHand OS may execute as though they were running on the bare iron.  
A manager that is added to a management group but is not started on a storage system until it  
is needed to regain quorum.  
A logical entity that is made up of storage on one or more storage systems. It can be used as  
raw data storage or it can be formatted with a file system and used by a host or file server.  
volume lists  
volume set  
For release 7.0 and earlier, provide the link between designated volumes and the authentication  
groups that can access those volumes. Not used in release 8.0 and later.  
Two or more volumes used by an application. For example, you may set up Exchange to use two  
volumes to support a StorageGroup: one for mailbox data and one for logs. Those two volumes  
make a volume set.  
37  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
volume size  
The size of the virtual device communicated to the operating system and the applications.  
VSS Provider  
HP StoreVirtual VSS Provider is the hardware provider that supports the Volume Shadow Copy  
Service on the HP StoreVirtual Storage.  
VSS  
Volume Shadow Copy Service  
writable space  
38 Glossary  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Index  
network for Multi-Site SAN, 6  
document  
related information, 31  
documentation  
Symbols  
2-site configurations  
primary site designation in, 17  
HP website, 31  
providing feedback on, 32  
A
adding  
E
additional capacity to existing sites, 28  
site, 27  
editing a site, 27  
storage systems to Multi-Site cluster, 28  
alternative Multi-Site SAN configurations, 18  
application clusters  
setting up in a Multi-Site SAN environment, 17  
application server  
F
Failover Manager  
best practices, 6  
capability of Multi-Site SAN, 5  
common configurations with managers, 13  
common configurations with recommended Failover  
Manager, 15  
configuring, 24  
installing, 25  
typical configuration with 3rd site, 13  
connecting to Multi-Site SAN, 12  
application servers  
assigning to sites, 6  
B
benefits of a Multi-Site SAN, 5  
best practices  
G
failover manager, 6  
implementing Multi-Site SAN network, 5  
installing Failover Manager, 25  
quorum and manager configuration, 15  
sites and quorum managers, 13  
glossary  
for LeftHand OS software and HP StoreVirtual Storage,  
H
C
help  
capacity, adding to sites, 28  
changing cluster type, 27  
clusters  
obtaining, 30  
high availability  
data protection level, 16  
site and manager configuration, 12  
HP  
changing from Multi-Site to standard, 27  
creating with Multi-Site wizard, 21  
removing storage systems from Multi-Site, 29  
CMC, viewing sites in, 26  
common Multi-Site SAN network designs, 6  
configurations, alternative Multi-Site SAN, 18  
configuring  
technical support, 30  
I
implementing the Multi-Site SAN, 20  
Insight Remote Support software, 30  
installation  
data protection level, 16  
Failover Manager, 24  
managers for Multi-Site SAN, 24  
regular managers, 24  
preparing for, 20  
installing the Multi-Site SAN, 20  
M
sites and quorum managers, 12  
contacting HP, 30  
converting an existing SAN to a Multi-Site SAN, 23  
creating  
management group, 21  
Multi-Site clusters and volumes, 21  
customer self repair, 30  
management group  
creating, 21  
manager  
common configurations with Multi-Site SANs, 13  
configuration best practices, 15  
configuring Failover Manager, 24  
configuring for high availability and redundancy, 12  
configuring for Multi-Site SAN, 24  
configuring regular, 24  
D
data protection  
configuring for high availability, 16  
deleting a site, 27  
designating a primary site, 27  
designing  
failover, for Multi-Site SAN, 5  
failover, in typical 3rd site configuration, 13  
overview, 24  
map view  
39  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
for sites, 26  
servers  
assigning to sites, 6  
removing from a site, 29  
setting up  
MPIO and multiple subnets, 12  
Multi-Site cluster  
creating, 21  
removing storage systems from, 29  
wizard, 23  
application clusters in a Multi-Site SAN environment,  
MPIO with multiple subnets, 12  
multiple subnets for a Multi-Site SAN, 9  
Multi-Site SAN  
alternative configurations, 18  
common configurations with recommended Failover  
Manager, 15  
sites  
adding, 27  
common network designs, 6  
converting from an existing SAN, 23  
implementing, 20  
adding capacity to, 28  
assigning servers to, 6  
configuring for high availability and redundancy, 12  
deleting, 27  
installing, 20  
multiple VIPs as feature of, 9  
overview, 5  
preparing to implement, 20  
designating primary, 27  
editing, 27  
map view, 26  
overview, 25  
N
removing servers from, 29  
removing storage systems from, 29  
viewing in the CMC, 26  
storage systems  
network  
requirements for performance considerations, 5  
network design  
common designs for Multi-Site SAN, 6  
adding to sites, 28  
removing from a site, 29  
subnets  
setting up multiple for a Multi-Site SAN, 9  
setting with MPIO, 12  
Subscriber's Choice, HP, 30  
support software, remote, 30  
O
overview  
managers, 24  
Multi-Site SAN, 5  
sites, 25  
P
T
performance and network requirements, 5  
planning  
technical support  
HP, 30  
preparing to install, 20  
primary site  
service locator website, 31  
U
designating, 27  
designation in 2-site configurations, 17  
using the Multi-Site cluster wizard, 23  
Q
V
quorum  
viewing sites in the console, 26  
VIP  
configuration best practices, 15  
sites and quorum managers, 13  
as feature of Multi-Site SAN, 9  
volumes  
R
creating with Multi-Site SAN wizard, 21  
rack stability  
W
warning, 30  
redundancy  
warning  
site and manager configuration for, 12  
related documentation, 31  
remote support software, 30  
removing  
rack stability, 30  
websites  
customer self repair, 30  
HP, 31  
servers from a site, 29  
storage systems from a site, 29  
storage systems from Multi-Site cluster, 29  
HP Subscriber's Choice for Business, 30  
product manuals, 31  
wizard, Multi-Site clusters, 21  
S
SAN, converting existing to Multi-Site, 23  
server, application  
connecting to Multi-Site SAN, 12  
40 Index  
Download from Www.Somanuals.com. All Manuals Search And Download.  

Graco Marine Radio 312497P User Manual
Grizzly Bread Maker H5383 User Manual
Haier Washer XQS70 98 User Manual
Hamilton Beach Water Dispenser D50042 User Manual
HANNspree Flat Panel Television LT0B 15A1 User Manual
Harrington Hoists Saw EAC700 User Manual
Hasbro Baby Toy 6896930000 User Manual
HP Hewlett Packard Computer Drive 460i User Manual
HP Hewlett Packard Photo Printer V Series User Manual
HP Hewlett Packard Water Dispenser 5381A User Manual