Best Practices; Remote Snapshots With Volume Replication; Example Configuration; How It Works - HP StoreVirtual 4000 User Manual

Best practices

Remote snapshots with volume replication

Use remote snapshots in conjunction with local, synchronous volume replication, known as Network
RAID. Using remote snapshots alone, any data written to the primary volume since the most recent
remote snapshot was created will be unavailable if the primary volume is unavailable.
However, you can lessen the impact of primary volume failure by using Network RAID. Network
RAID allows you to create up to four copies of a volume on the same cluster of storage systems as
the primary volume. The only limitation is that the cluster must contain at least as many storage
systems as replicas of the volume. Replicating the volume within the cluster ensures that if a storage
system in the cluster goes down, replicas of the volume elsewhere in the cluster will still be available.
For more information about Network RAID and data protection levels, see the chapter "Provisioning
Storage" in the HP LeftHand Storage User Guide.

Example configuration

Figure 8 (page 34)
number of storage systems. For information about creating clusters and volumes, see the HP LeftHand
Storage User Guide.
In the production location, create a management group and a cluster of three storage systems.
Create volumes on the cluster and set the data protection level to Network RAID- 1 0.
Configure the production application server to access the primary volume via iSCSI.
In the backup location, create a second management group and a cluster of three storage
systems.
Create a schedule for making remote snapshots of the primary volume. See
snapshots" (page
NOTE: Data protection levels are set independently for primary and remote volumes.

How it works

If one of the storage systems in the primary location fails, the primary volume will still be available.
If all of the storage systems fail, or if the application server fails, then failover to the backup
application server occurs, and the remote snapshot(s) becomes available.
36 Sample Remote Copy configurations
uses three storage systems per cluster. However, this scenario can use any
23).
"Scheduling remote