Designing Disaster Recovery Clusters using Metroclusters and Continentalclusters, Reprinted October 2011 (5900-1881)

move the application packages back to the primary site are different depending on the roles of
the Remote Copy volume groups on either site.
• Failback to the Primary Site
The following procedure applies to the situation where the Remote Copy volume group has a
status of “Primary" on the primary site and "Primary-Rev" on the recovery site.
1. While the recovery package is still running, execute the setrcopygroup recover
command which will establish the replication from the recovery site to the primary site.
This will change the role of the Remote Copy volume group to "Secondary-Rev" at the
primary site.
2. When the Remote Copy volume group is synced completely, halt the Continentalclusters
recovery packages at the recovery site.
# cmhaltpkg <pkg_name>
This will halt any applications, remove any floating IP addresses, unmount file systems
and deactivate volume groups that are configured as part of the recovery package. The
roles of the Remote Copy volume groups will remain “Primary-Rev” at the recovery site
and “Secondary-Rev” at the primary site.
3. Start the cluster at the primary site. Assuming they have been properly configured, the
Continentalclusters primary packages must not start. The monitor package should start
automatically, if configured.
4. Manually start the Continentalclusters primary packages at the primary site.
# cmrunpkg <pkg_name>
# cmmodpkg -e <pkg_name>
Metrocluster will restore the roles of the Remote Copy volume group back to "Primary"
on the primary site and "Secondary" on the recovery site.
Scenario 2
The primary site 3PAR storage system experienced a catastrophic hardware failure and all data
was lost on the storage system.
• Failback to the Primary Site
In this scenario, either the storage system is repaired or a new 3PAR storage system is
commissioned at the primary site. Before the application can fail back to the primary site, the
storage system in the recovery site (now is the source storage) needs to establish or restore
the replication relationship with the new or repaired storage system in the primary site (now
is the destination storage). See the 3PAR Remote Copy User Guide to rebuild or restore the
Remote Copy volume groups configured in the storage system. Once the Remote Copy volume
groups re-built or restored and the destination storage is synchronized with the source storage,
the packages can be failed back to the primary site.
Scenario 3
The primary site has lost power, which only impacts the host systems in the source disk site. The
source disk site is down, but the 3PAR storage system and Remote Copy links to the recovery site
are up and running.
• Failback in Scenario 3
In this scenario the storage systems in both sites are up and running. The Remote Copy links
are functional. When the recovery packages are up and running on the recovery site,
Metrocluster automatically switches the replication direction; the new data written on the
recovery site's storage system is replicated to the primary site's storage system.
After the primary site host systems are back online, halt the recovery packages, start the cluster
at the primary site and start the primary packages at the primary site.
330 Building Disaster Recovery Serviceguard Solutions Using Metrocluster with 3PAR Remote Copy