HP P6000 Replication Solutions Manager User Guide (T3680-96089, October 2012)

For example, say that you use the wizard to create and save a round robin job that maintains
three replicas of a host volume. The first three times that you run a job instance, a new replica will
be created and added to the wizard's replica repository; and, each replica will have its own
underlying virtual disks. When you run a job instance four times or more, the oldest replica will
be deleted from the repository and a new replica added. However, no additional underlying virtual
disks will required for the new replica.
Snapclones (host volume)
Snapclone replication of a host volume instantly creates independent point-in-time copies of the
virtual disks that underlie a host volume. The copies are called snapclones.
The snapclone property indicates whether the host volume can be locally replicated using the
snapclone method. Values are:
• Yes. All virtual disks that underlie the host volume comply with snapclone guidelines. Snapclone
replication can be performed.
• No. One or more virtual disks that underlie the host volume do not comply with snapclone
guidelines. Snapclone replication cannot be performed.
See also virtual disks Snapclones, Snapclone FAQ and Snapclone guidelines.
Snapshots (host volume)
Snapshot replication of a host volume instantly creates virtual, point-in-time copies of the virtual
disks that underlie a host volume. The copies are called snapshots.
The snapshot property indicates whether the host volume can be locally replicated using the snapshot
method. Values are:
• Yes. All virtual disks that underlie the host volume comply with snapshot guidelines. Snapshot
replication can be performed.
• No. One or more virtual disks that underlie the host volume do not comply with snapshot
guidelines. Snapshot replication cannot be performed.
See also virtual disks Snapshots, Snapshot types, Snapshot FAQ and Snapshot guidelines.
Snapshot FAQ
• How can I tell a snapshot from other types of virtual disks?
Because snapshots are not independent virtual disks, they are identified differently than original
virtual disks. See virtual disks Types.
• How long does it take to create a snapshot?
A snapshot requires only a matter of seconds, no matter how large the original virtual disk.
• If it is virtual, can a host write to a snapshot?
Yes. A snapshot is functionally equivalent to a physical disk with both read and write capability.
• After I create a snapshot, can I delete the original virtual disk?
No. A snapshot always relies, at least in part, on the original (active) virtual disk for data. If
the original virtual disk is deleted, its associated snapshot becomes unusable. A snapshot
should be thought of as a temporary copy.
• Can I make multiple snapshots of an original virtual disk?
Yes. However, there is a limit. See virtual disks Snapshot guidelines.
• What is the maximum number of snapshots on a storage system?
There is no limit. However, the greater the number of snapshots, the longer it takes to shut
down the storage system during maintenance and upgrade activities.
136 Host volumes