SnapMirror Commands

Manage SnapMirror

The snapmirror commands enable you to create and manage data protection mirrors, extended data protection relationships, and load-sharing mirrors.

These commands are available to the cluster and Vserver administrators.

Note that there are "Pre 8.2" relationships: (1) load-sharing relationships; (2) data protection relationships with the source volume on a storage system running clustered Data ONTAP 8.1; (3) data protection relationships that existed before the source and destination storage systems were upgraded from clustered Data ONTAP 8.1 to clustered Data ONTAP 8.2 and later and have not yet been converted to ones with Data ONTAP 8.2 capabilities. These relationships have the same limitations as on Data ONTAP 8.1. In particular, only snapmirror commands present on Data ONTAP 8.1 can be used for these relationships. The "Relationship Capability" field, as shown in the output of the snapmirror show command, is set to "Pre 8.2" for these relationships. "Pre 8.2" data protection relationships can only be created and managed by the cluster administrator; load-sharing relationships which are all "Pre 8.2" can be created and managed by either a cluster or Vserver administrator.

Data protection relationships that existed before the source and destination storage systems were upgraded from Data ONTAP 8.1 will be auto-converted to "8.2 and above" with full capabilities when a Vserver peering relationship is set up between the source and destination Vservers. Relationships which have both the source and destination in the same Vserver and therefore require no Vserver peering relationship will be converted on the first boot when all nodes in the storage system are running Data ONTAP 8.2 or later. Note that since there is no "8.2 and above" implementation of load-sharing relationships, there is no conversion of load-sharing relationships to "8.2 and above".

When a SnapMirror relationship is created with the type of the relationship specified as data protection (DP), an extended data protection (XDP) relationship will be created. This relationship will provide the same functional behavior as the DP type in terms of Snapshot copy selection and retention. This is achieved by using a policy which has the rule to replicate all Snapshot copies. There is an exception to this relationship creation behavior of overriding of the type DP. If a relationship of type DP in the opposite direction already exists, the new relationship will also be of type DP. The type DP will eventually be deprecated and applications should not use this type when creating new relationships. When the type is specified as DP or when no type is specified, if a policy of type async-mirror is specified that does not have the rule to replicate all Snapshot copies, the snapmirror create command will fail.