Best Practices; Remote Snapshots With Volume Replication; Example Configuration; High Availability Configuration During Failback - HP StorageWorks P4000 User Manual

Figure 12 High availability configuration during failback
.

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 StorageWorks P4000 SAN Solution user guide.

Example configuration

Figure 10 on page 44 uses three storage systems per cluster. However, this scenario can use any
number of storage systems. For information about creating clusters and volumes, see the HP
StorageWorks P4000 SAN Solution 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-10.
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" on page 29.
46 Sample Remote Copy configurations
"Scheduling remote