Dell PowerVault ME5 Series Storage System CLI Reference Guide

Creates a replication set for a specified volume or volume group.

This command is not applicable to a system with SAS controller modules.

A maximum of 1 replication set per volume can be created.

This command designates the specified source volume or volume group as the primary volume or volume group, creates the secondary volume or volume group, and creates the internal snapshots 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.

• 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.

create replication-set

peer-connection <peer-connection-ID>

primary-volume <volume-ID>|<volume-group-ID>

[queue-policy discard|queue-latest]

[secondary-pool A|B]

[secondary-volume-name <name>]

[snapshot-basename <basename>]

[snapshot-count <#>]

[snapshot-history disabled|off|secondary|both]

[snapshot-retention-priority never-delete|high|medium|low]

name

Specifies the name or serial number of the peer connection on which to create the replication set

Specifies the name or serial number of a volume or volume group on the local system. Volume-groups must be specified with the name and .* notation used in mapping.

Optional. Specifies the action to take when a replication is running and a new replication is requested.

• discard: Discard the new replication request.
• queue-latest: Take a snapshot of the primary volume and queue the new replication request. If the queue contained an older replication request, discard that older request. A maximum of one replication can be queued. This is the default.

Optional. Specifies an existing virtual pool on the remote peer. If this is not specified, the system uses the corresponding pool on the remote system. For example, if pool A is used on the local system, pool A is used on the remote system. If this is not specified and the corresponding pool on the remote side does not exist, this command fails.

Optional. Specifies a name for the secondary volume. If this is not specified, the name from the primary volume is used. For volume-group targets, all contained volume names must be unique. Input rules:

• The value is case-sensitive.
• The value can have a maximum of 32 bytes.
• The value can include spaces and printable UTF-8 characters except: " , < \
• A value that includes a space must be enclosed in double quotes.

Optional if snapshot-history is set to disabled or off. Required if snapshot-history is set to secondary or both. Specifies a prefix to help you identify replication snapshots. Input rules:

• The value is case sensitive.
• The value can have 1 to 24 bytes.
• The value can include spaces and printable UTF-8 characters except: " ' , < > \
• A value that includes a space must be enclosed in double quotes.

There is no default.

Specifies the number of snapshots that are taken of the replication volume to retain, from 1 to 16. When a new snapshot exceeds this limit, the oldest snapshot in the snapshot history is deleted.

If not specified, the snapshot count defaults to 1 during command execution with snapshot-history enabled.

The snapshot-count setting can be changed at any time. Its value must be greater than the number of existing snapshots in the replication set, regardless of whether snapshot-history is enabled.

Optional. Specifies whether to maintain a replication snapshot history for the replication set, as previously described.

• disabled or off: A snapshot history is not kept. If this parameter is disabled after a replication set has been established, any existing snapshots will be kept, but not updated. This option is the default.
• secondary: A snapshot history set is kept on the secondary system for the secondary volume, using snapshot-count and snapshot-basename settings.
• both: A snapshot history is kept for the primary volume on the primary system and for the secondary volume on the secondary system. Both snapshot histories use the same snapshot-count and snapshot-basename settings

Optional. For virtual storage, this specifies the retention priority for history snapshots, which is used when automatic deletion of snapshots is enabled by using the "set snapshot-space" command. In a snapshot tree, only leaf snapshots can be deleted automatically. Deletion of snapshots based on retention priority is unrelated to deleting the oldest snapshots to maintain a snapshot count.

• never-delete: Snapshots are never automatically deleted to make space. The oldest snapshot in the snapshot history is deleted once the snapshot-count has been exceeded. This is the default.
• high: Snapshots can be deleted after all eligible medium-priority snapshots have been deleted.
• medium: Snapshots can be deleted after all eligible low-priority snapshots have been deleted.
• low: Snapshots can be deleted.

Specifies a name for the replication set. Input rules:

• The value is case-sensitive.
• The value can have a maximum of 32 bytes.
• The value can include spaces and printable UTF-8 characters except: " , < \
• A value that includes a space must be enclosed in double quotes.

# create replication-set peer-connection Peer1 primary-volume Vol1 RS1

# create replication-set peer-connection Peer1 primary-volume VG1.* RS1

# create replication-set peer-connection Lab primary-volume vol2 secondary-pool A snapshot-retention-priority never-delete snapshot-history both snapshot-basename repsnapVol2 snapshot-count 5 repset2

recover replication-set

replicate

resume replication-set

set replication-set

show replication-sets

suspend replication-set