Run this command only on recovery cluster nodes. This command succeeds only when Continentalclusters is configured for maintenance mode. The command checks for the following conditions to successfully disable a recovery group:

•The recovery package is down and package switching is disabled.

•The primary cluster and the primary package are up. If the cluster is down or unreachable, use the force -foption to forcefully disable the recovery group.

WARNING! When you use the force option, ensure that the primary package and the cluster are not down due to a primary site failure.

•The monitor package is up and running in the recovery cluster.

Moving a Recovery Group out of the Maintenance Mode

Run the following command to enable a recovery group and move it out of the maintenance mode:

cmrecovercl -e -g <recovery group>

Where:

<recovery group> is the name of the recovery group to be enabled and moved out of the maintenance mode.

You can run this command only on recovery cluster nodes. The command succeeds only when Continentalclusters is configured for maintenance mode. Following are the conditions that need to be met for the recovery group to be enabled and moved out of the maintenance mode:

•For recovery groups configured with a rehearsal package, the rehearsal package is halted and package switching is disabled.

•The monitor package is up and running in the recovery cluster.

Performing Cluster Recovery

When a CLUSTER_ALARM is issued, there may be a need for a cluster recovery using the recovery command, cmrecovercl, which is enabled for use by the root user. Cluster recovery is carried out at the site of the recovery cluster by using thecmrecovercl command. The cmrecovercl command will only recover recovery groups that are enabled for recovery and are not in the maintenance mode.

# cmrecovercl

Issuing this command will halt any configured data replication activity from the failed cluster to the recovery cluster, and will start all configured recovery packages on the recovery cluster that are pre-configured in recovery groups. A recovery group is the basic unit of recovery used in Continentalclusters configuration. This command will fail if a cluster alarm has not been issued.

If option “-g RecoveryGroup” is specified with the recovery command, then the recovery process of halting data replication activity and starting of the recovery package will only be done for the specified recovery group.

After the cmrecovercl command is issued, there is a delay of at least 90 seconds (per recovery group) while the command ensures that the package is not active on another cluster.

Cluster recovery is done as a last resort, after all other approaches to restore the unavailable cluster have been exhausted. It is important to remember that cluster recovery sets in motion a process that cannot be easily reversed. Unlike the failover of a package from one node to another, failing a package from one cluster to another normally involves a significant quantity of data that is being accessed from a new set of disks. Returning control to the original cluster will involve resynchronizing this data and resetting the roles of the clusters in a process that is easier for some data replication techniques than others.

44 Designing Continentalclusters