Replication can be configured from any ZFS Storage Appliance to any other ZFS Storage Appliance regardless of whether each is part of a cluster and whether the ZFSSA's cluster peer has replication configured in either direction, except for the following constraints:
Configuring replication from both peers of a cluster to the same replication target is unsupported, but a similar configuration can be achieved using two different IP addresses for the same target ZFSSA. Administrators can use the multiple IP addresses of the target ZFSSA to create one replication target on each cluster head for use by that head.
When configuring replication between cluster peers, configure replication with both controllers in the CLUSTERED state. Do not use private network addresses and use separate replication targets for each controller's pools.
The following rules govern the behavior of replication in clustered configurations:
Replication updates for projects and shares are sent from whichever cluster peer has imported the containing storage pool.
Replication updates are received by whichever peer has imported the IP address configured in the replication action on the source. Administrators must ensure that the head using this IP address will always have the storage pool containing the replica imported. This is ensured by assigning the pool and IP address resources to the same head during cluster configuration.
Replication updates (both to and from an ZFSSA) that are in progress when an ZFSSA exports the corresponding storage pool or IP address (as part of a takeover or failback) will fail. Replication updates using storage pools and IP addresses unaffected by a takeover or failback operation will be unaffected by the operation.
For details on clustering and cluster terminology, review the Chapter 10, Cluster Configuration.