11.0 HP StoreVirtual Storage Remote Copy User Guide (AX696-96306, September 2013)

Table 3 Snapshot retention policy and maximum number of retained snapshots (continued)
Maximum number of snapshots retainedScheduled remote snapshot retention policy
n + 2 primary snapshots older than nx + 2 remote
snapshots older than x
n of days for primary snapshots x of days for remote
snapshots
n + 2 primary snapshots older than nx + 2 remote
snapshots older than x
n of weeks for primary snapshots x of weeks for remote
snapshots
• A remote snapshot is deleted only after its corresponding primary snapshot is deleted.
Additionally, a remote snapshot is deleted only after its counterpart primary snapshot. You
cannot retain fewer remote snapshots than primary snapshots when setting your retention
policies.
NOTE: Over the course of time, through deletion of primary snapshots, if you accumulate more
remote snapshots than primary snapshots, the remote snapshots become regular snapshots when
their corresponding primary snapshots are deleted. You can identify them as remote snapshots by
their names, since the naming convention is established as part of creating the remote snapshot
schedule.
Best practices
• Retain at least two primary snapshots to ensure that only incremental copying is required for
remote snapshots.
• Review your remote copy schedule to ensure that the frequency of the remote copies correlates
to the amount of time required to complete a copy.
Use the checklist in Table 4 (page 9) to help plan scheduled remote snapshots.
Table 4 Scheduled Remote Copy planning checklist
CharacteristicConfiguration category
Scheduled snapshot
Start time
• Start date (mm/dd/yyyy) for the schedule to begin
• Start time (mm:hh:ss) for the schedule to begin
Recurrence
• Recurrence is a yes or no choice. Do you want to take a remote snapshot one time in
the future and not have it recur, or do you want a remote snapshot to be taken on a
regular schedule?
• Frequency (minutes, hours, days, or weeks) determines the interval between recurring,
scheduled, remote snapshots.
Primary setup
Select one of the following options:Retention
• Maximum number of snapshots (#)
• Set period of time (minutes, hours, days, or weeks)
Remote setup
The management group that contains the remote snapshotManagement group
The remote volume for the remote snapshotsVolume
Select one of the following options:Retention
• Maximum number of snapshots. This number equals completed snapshots only. In-progress
snapshots take additional space on the cluster while copying. Also, the system will not
Using schedules for Remote Copy 9