Remote mirror integration
When you use storage solutions with mirror technologies in combination with IBM® Storage Protect Snapshot, certain criteria must be met by the environment to integrate backup, restore, and cloning operations. For IBM System Storage® SAN Volume Controller and IBM System Storage DS8000® series, mirror technologies are labeled Global Mirror and Metro Mirror. For IBM XIV® Storage System, mirror technologies are labeled Synchronous Remote Mirroring and Asynchronous Remote Mirroring.
- SAN Volume Controller
- IBM Storage Protect Snapshot backs up application data consistently on SAN Volume Controller storage solutions with volumes that are simultaneously used as Metro Mirror or Global Mirror sources. You can configure either the sources or the targets of the Remote Mirror to be selected as the sources for the FlashCopy® backup. In addition, do not use FlashCopy targets as Global Mirror or Metro Mirror sources.
- IBM System Storage DS8000
- IBM Storage Protect Snapshot backs up DS8000 storage solutions with volumes that are simultaneously used as Global Mirror or Metro Mirror sources. In contrast to SAN Volume Controller, you can configure only the sources of the Global Mirror or Metro Mirror to be selected as the sources of the snapshot backup. When you use IBM Storage Protect Snapshot in this environment, do not use snapshot targets as Global Mirror and Metro Mirror sources.
- IBM XIV Storage System
- IBM Storage Protect Snapshot can back up application data consistently on XIV storage solutions with volumes that are simultaneously used as Synchronous Remote Mirroring or Asynchronous Remote Mirroring sources. You can configure either the sources or the targets of the Remote Mirror to be selected as the sources for the FlashCopy backup.
Storage solutions that use mirror technologies with IBM Storage Protect
Snapshot must have the correct environment. The
following list describes the criteria that must be met to ensure mirroring works correctly.
- The connectivity state must be online.
- The cluster partnership between the primary and secondary clusters must be configured before you
use IBM Storage Protect
Snapshot. The following list
identifies what you must configure when you are setting up the cluster partnership:
- IBM Storage Protect Snapshot is installed on the production and backup host on the local site (primary cluster).
- IBM Storage Protect Snapshot is installed on all systems, including the takeover and standby servers, running at the remote site (secondary cluster).
- The local site contains the primary storage cluster for the production hosts. The primary cluster has data that is replicated to a secondary cluster on the remote site or to the same cluster.
- For intersystem copying, the remote site contains the mirror volumes in another storage cluster. In addition, the remote site also hosts the takeover and standby servers.
- SAN Volume Controller supports both intrasystem and intersystem Metro and Global Mirror.
- For XIV Synchronous Remote Mirroring and Asynchronous Remote Mirroring, configure either the source or the targets as a source for the snapshot backup.
- IBM Storage Protect
Snapshot uses a consistency group on
the SAN Volume Controller and XIV storage solutions for the FlashCopy or
snapshot. A consistency group is a group of volumes that are associated with a snapshot pair, which
is a snapshot group of two corresponding instant copies of data, that is, point-in-time copies of a
volume. For the snapshot pair, the logically related data must be kept consistent across the
volumes. The snapshot consistency group can be used for a consistent point-in-time copy for an
application or database that spans multiple volumes. The following list identifies more information
about using consistency groups with IBM Storage Protect
Snapshot:
- SAN Volume Controller
-
- A consistency group contains a list of snapshot or Remote Copy relationships.
- The IBM Storage Protect Snapshot software creates a snapshot consistency group on the secondary site to build a consistency unit between the source and target of the snapshot.
- You must define the consistency group for the mirror relationships between the master and auxiliary virtual disks.
- For Metro and Global Mirror, the state of the consistency group must be consistently synchronized.
- XIV
-
- The operational state of mirror must be operational.
- A consistency group contains a list of volumes.
- A consistency group that contains all of the remote copy target volumes must exist before you start the snapshot on the remote system. Apply the storage commands to the consistency group to simplify management.
- The mirror relationship between the master and slave volumes must be defined in the consistency
group.
The master is where source volumes are located for the remote replication. The slave is where target volumes are located.
- For XIV synchronous mirroring, the state of the consistency group must be consistently synchronized.
- For XIV asynchronous mirroring, the state of the consistency group must be RPO_OK.
- For Metro Mirror and Synchronous Remote Mirroring, the write operation is committed to the host after the data is written to both the source and target volumes.
- For Global Mirror and Asynchronous Remote Mirroring, the write operation is committed to the host immediately after the data is written to the source volume.
- In terms of master and slave sites, the master site is where source volumes are located for the remote replication. The slave site is where target volumes are located. When a disaster occurs or when maintenance is necessary, the roles of master site and slave site can be changed.
The following figure illustrates the hosts and volumes that are involved in remote mirroring that uses Metro and Global mirrors.
