The snapmirror update command updates the destination volume or non-Data ONTAP endpoint of a SnapMirror relationship. The snapmirror update command behaves differently for data protection (DP), extended data protection (XDP) and load-sharing (LS) relationships. Refer to the -type parameter of the snapmirror create command to understand different types of relationships supported by SnapMirror.

The snapmirror update command performs an incremental transfer.

Before using this command, the relationship must be initialized using the snapmirror initialize or snapmirror initialize-ls-set commands.

For data protection SnapMirror relationships with volumes as endpoints, the snapmirror update command makes the destination volume an up-to-date mirror of the source volume with the following steps:

You can use the snapmirror update command to update a specific load-sharing mirror that lags behind up-to-date destination volumes in the set of load-sharing mirrors. An update to the lagging load-sharing mirror should bring it up to date with the other up-to-date destination volumes in the set of load-sharing mirrors.

For extended data protection (XDP) relationships with a snapmirror policy of type async-mirror , a snapmirror update always creates a new Snapshot copy on the source volume. Depending on the rules in the policy, the command might transfer just the newly created Snapshot copy or all Snapshot copies that are newer than the common Snapshot copy including the newly created Snapshot copy to the destination volume.

For extended data protection (XDP) relationships with a snapmirror policy of type vault , a snapmirror update does not create a new Snapshot copy on the source volume but transfers only selected Snapshot copies that are newer than the common Snapshot copy to the destination volume. (Those older than the common copy can be transferred by using the -source-snapshot parameter.) Snapshot copies are selected by matching the value of -snapmirror-label of a Snapshot copy with the value of -snapmirror-label of one of the rules from the corresponding SnapMirror policy associated with the SnapMirror relationship. All matching Snapshot copies are incrementally transferred to the destination volume.

For extended data protection (XDP) relationships with a snapmirror policy of type mirror-vault , a snapmirror update always creates a new Snapshot copy on the source volume and transfers only selected Snapshot copies that are newer than the common snapshot copy. The newly created Snapshot copy is always selected.

For extended data protection (XDP) relationships with a snapmirror policy of type vault or mirror-vault , the snapmirror update command also manages expiration of Snapshot copies on the destination volume. It does so by deleting Snapshot copies that have exceeded the value of -keep for the matching rule from the corresponding SnapMirror policy associated with the SnapMirror relationship. Snapshot copies that match the same -snapmirror-label will be deleted in oldest-first order.

For relationships with a policy of type strict-sync-mirror or sync-mirror , this command creates a new common Snapshot copy and designates it as the exported Snapshot copy on the destination volume. It updates the destination read-only view because IO is redirected to the new exported Snapshot copy. Clients could experience a brief latency spike during this process as the primary IO is temporarily fenced. This command is allowed only when the relationship-status is InSync. The command retains two pairs of common Snapshot copies and deletes the older ones.

For data protection relationships, the parameter -source-snapshot is optional and only allows for the transfer of Snapshot copies newer than the common Snapshot copy up to the specified -source-snapshot .

For extended data protection (XDP) relationships the parameter -source-snapshot is optional.

For extended data protection (XDP) relationships with a snapmirror policy of type vault or mirror-vault , the parameter -source-snapshot allows transfer of a Snapshot copy that is older than the common Snapshot copy and/or might not be selected for transfer based on policy-based selection of a scheduled update transfer.

For extended data protection (XDP) relationships with a snapmirror policy of type async-mirror , the snapmirror update with parameter -source-snapshot does not create a new Snapshot copy on the source volume. Depending on the rules in the policy, the command might transfer just the specified Snapshot copy or Snapshot copies that are newer than the common Snapshot copy upto and including the specified Snapshot copy to the destination volume.

After the snapmirror update command successfully completes, the last Snapshot copy transferred is designated as the new exported Snapshot copy on the destination volume. If an update to an extended data protection (XDP) relationship specifies a Snapshot copy using the -source-snapshot parameter that is older than the common snapshot, after the snapmirror update successfully completes, the exported Snapshot copy on the destination volume will remain unchanged.

If the snapmirror update does not finish successfully—​for example, due to a network failure or because a snapmirror abort command was issued—​a restart checkpoint might be recorded on the destination volume. If a restart checkpoint is recorded, the next update restarts and continues the transfer from the restart checkpoint. For extended data protection (XDP) relationships, the next update will restart and continue the old transfer regardless of whether the Snapshot copy being transferred is a matching Snapshot copy or not.

This command is supported for SnapMirror relationships with the field "Relationship Capability" showing as either "8.2 and above" or "Pre 8.2" in the output of the snapmirror show command.

For relationships with "Relationship Capability" of "8.2 and above" , you can track the progress of the operation using the snapmirror show command.

For relationships with "Relationship Capability" of "Pre 8.2" , a job will be spawned to operate on the SnapMirror relationship, and the job id will be shown in the command output. The progress of the job can be tracked using the job show and job history show commands.

For Vserver SnapMirror relationships, the snapmirror update command makes the destination Vserver an up-to-date mirror of the source Vserver.

The snapmirror update command must be used from the destination Vserver or cluster.

To update the mirror relationship between the destination endpoint vs2.example.com:dept_eng_dp_mirror3 and its source endpoint, type the following command:

For relationships with "Relationship Capability" of "Pre 8.2" , to update the mirror relationship between the destination endpoint cluster2://vs2.example.com/dept_eng_dp_mirror3 and its source endpoint, type the following command:

To update the Vserver SnapMirror relationship between destination endpoint dvs1.example.com: and its source endpoint, type the following command: