CLI Guide

For the maximum number of replication sets that can be created, see the “System configuration limits” topic
in the PowerVault Manager help.
This command designates the specified source volume or volume group as the primary volume or volume
group. This command also creates the secondary volume or volume group, and creates the internal snapshots
that are required to support replications.
• A replication set for a volume consumes two internal snapshots each for the primary volume and the
secondary volume if the queue policy is set to discard, or three each if the queue policy is set to
queue-latest.
• A replication set for a volume group consumes two internal volume groups if the queue policy is set to
discard, or three if the queue policy is set to queue-latest. Each internal volume group contains a
number of volumes equal to the number of volumes in the base volume group.
Internal snapshots and internal volume groups count against system limits, but do not display.
A peer connection must already be defined to create and use a replication set.
The command fails if the secondary volume names exist, or if the local system cannot reach the remote
system.
Secondary volumes cannot be mapped, moved, expanded, deleted, or participate in a rollback operation.
Create a snapshot of the secondary volume, and use the snapshot for mapping and accessing data.
A volume or volume group can belong to only one replication set. If the volume group is already in a replication
set, individual volumes may not be included in separate replication sets. The maximum number of individual
volumes that can be replicated is 32. If a volume group is being replicated, the maximum number of volumes
that can exist in the group is 16.
A replication set can be configured to maintain a replication snapshot history. As part of handling a replication,
the replication set will automatically take a snapshot of the primary and/or secondary volumes, thereby
creating a history of data that has been replicated over time. This feature can be enabled for a secondary
volume or for a primary volume and its secondary volume, but not for a volume group. When this feature is
enabled:
• For a primary volume, when a replication starts it creates a snapshot of the data image being replicated.
• For a secondary volume, when a replication successfully completes it creates a snapshot of the data
image that is just transferred to the secondary volume. (This is in contrast to the primary volume
snapshot, which is created before the sync.) If replication does not complete, a snapshot is not created.
• The snapshots are named basename_nnnn, where nnnn starts at 0000 and increments for each
subsequent snapshot. If primary-volume snapshots are enabled, snapshots with the same name will exist
on the primary and secondary systems. The snapshot number is incremented each time that a replication
is requested, whether the replication completes. For example, if the replication was queued and removed
later from the queue.
• You can set the number of snapshots to retain, referred to as the snapshot count. This setting applies to
management of snapshots for both the primary and secondary volume. When the snapshot count is
exceeded, the oldest unmapped snapshot will be discarded automatically. If you reduce the snapshot
count setting (by using the set replication-set command) to a value less than the current number of
snapshots, the command will be rejected. Thus, you must manually delete the excess snapshots before
reducing the snapshot count setting
• If the replication set is deleted, any existing snapshots that are automatically created by snapshot history
rules are not deleted. You can manage those snapshots like any other snapshots.
• Manually creating a snapshot does not increase the snapshot count that is associated with the snapshot
history. Manually created snapshots are not managed by the snapshot history feature. If a volume already
exists with the name of the snapshot that is intended to be taken, the snapshot will not occur, and the
snapshot number is incremented.
• A snapshot that is created by this feature is counted against the system-wide maximum snapshots limit,
with the following result:
○ If the snapshot count is reached before the system limit, then the snapshot history is unchanged.
○ If the system limit is reached before the snapshot count, then the snapshot history stops adding or
updating snapshots.
• A mapped snapshot-history snapshot will not be deleted until after it is unmapped.
• The snapshot-basename and snapshot-count settings only take effect when snapshot-history is set to
secondary or both, although these settings can be changed at any time.
Minimum role
manage
Alphabetical list of commands 49