Remote Mirroring

Describes the concept and purpose of remote mirror volumes.

A remote mirror volume is a mirror volume with a source in another cluster. You can use remote mirrors for offsite backup, for data transfer to remote facilities, and for load and latency balancing for large websites. By mirroring the cluster's root volume and all other volumes in the cluster, you can create an entire mirrored cluster that keeps in sync with the source cluster.

Backup mirrors for disaster recovery can be located on physical media outside the cluster or in a remote cluster. If disaster strikes the source cluster, you can check the time of last successful synchronization to determine how current the backup is (see Mirror Status).

Once data volumes are created in a primary datacenter, the MapR administrator creates mirror volumes in a remote secondary datacenter. The following diagram illustrates the mirror relationship between these two volumes:

Note: When you use promotable mirrors, you must set up the volumes on the destination cluster in the same way as on the primary site. This means that volume names are the same and mount points are the same. If you use a hierarchical mounting structure (such as /A/B) on the primary site, you must recreate the same structure once you promote the mirror volumes at the secondary site.