Benefits Of Remote Copy; Planning For Remote Copy; Planning The Remote Snapshot; Prerequisites For Creating A Remote Snapshot - HP StorageWorks P4000 User Manual

Benefits of Remote Copy

Remote Copy maintains the primary volume's availability to application servers. Snapshots on the
primary volume are taken instantaneously, and are then copied to remote snapshots in the off-site
location.
Remote Copy operates at the block level, moving large amounts of data much more quickly than
file system copying.
Snapshots are incremental, that is, snapshots save only those changes in the volume since the last
snapshot was created. Therefore, failback may need to resynchronize only the latest changes
rather than the entire volume.
Remote Copy is robust. If the network link goes offline during the process, copying resumes where
it left off when the link is restored.

Planning for Remote Copy

Remote Copy works at the management group, cluster, volume, and snapshot levels. Review
2 on page 12 for common configurations at these levels.
Table 2 Remote Copy, SAN/iQ, and storage systems
Storage system
level
Management groups
Clusters
Volumes
Snapshots

Planning the remote snapshot

Prerequisites for creating a remote snapshot

Log in to both the management group that contains the primary volume and the management
group that contains the target cluster where the remote snapshot will be created.
Designate or create a remote volume in that remote management group.
Ensure there is enough space on the target cluster for the remote snapshot.
12 Understanding and planning Remote Copy
Remote Copy configuration
Create remote snapshots in the same management group or in a different manage-
ment group than the primary volume.
If using different management groups, the remote bandwidth setting of the manage-
ment group containing the remote volume determines the maximum rate of data
transfer to the remote snapshot.
Event notification tells you when copies complete or fail. It also notifies you if a re-
mote volume or snapshot is made primary or if the status of the connection between
management groups containing primary and remote volumes changes.
Create remote snapshots in the same cluster or in a cluster different from the primary
volume.
Primary volumes contain the data to be copied to the remote snapshot.
Data is copied to the remote snapshot via the remote volume.
The remote volume is a pointer to the remote snapshot. The remote volume has a
size of 0 bytes.
After data is copied from the primary snapshot to the remote snapshot, the remote
snapshot behaves as a regular snapshot.
Table