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

replication from the primary cluster. Finally, you need to move the recovery group out of the
maintenance mode by enabling it using the cmrecovercl -e command.
WARNING! Ensure that the storage system of the recovery group is synchronized with the
latest data and the replication environment is restored before the recovery group is moved
out of the maintenance mode. Failure to do so can result in the recovery package using
production data that was invalidated by the rehearsal run during a subsequent recovery.
For information on running a rehearsal process in your environment, see “Data Replication Rehearsal
in a Sample Environment” (page 104).
Notes on Packages in Continentalclusters
Packages have different behavior in Continentalclusters than in a normal Serviceguard environment.
There are specific differences in
• Startup and Switching Characteristics
• Network Attributes
From Continentalclusters version A.0.08.00 and above, you can configure the following package
types in a recovery group:
• Failover
• Oracle RAC Multi-node packages
• Complex workloads using SADTA
For details, see “Support for Complex Workloads in a Continentalclusters Environment using
SADTA” (page 125).
In the case of a multi-node package, a recovery process recovers all instances of the package in
a recovery cluster.
NOTE:
• System multi-node packages cannot be configured in Continentalclusters recovery groups.
Multi-node packages are supported only for Oracle with CFS or CVM environments.
• Starting with Continentalclusters version A.08.00, packages in Continentalclusters can be
configured as modular packages. For more information on configuring modular packages in
Continentalclusters, see “Configuring Modular Packages in Continentalclusters” (page 65).
Startup and Switching Characteristics
Normally, an application (package) can run on only one node at a time in a cluster. However, in
Continentalclusters, there are two clusters in which an application—the primary package or the
recovery package—could operate on the same data. Both the primary and the recovery package
must not be allowed to run at the same time. To prevent this, it is important to ensure that packages
are not allowed to start automatically and are not started at inappropriate times.
To keep packages from starting up automatically, when a cluster starts, set the AUTO_RUN
(PKG_SWITCHING_ENABLED used prior to Serviceguard A.11.12) parameter for all primary and
recovery packages to NO. Then use the cmmodpkg command with the -e <packagename> option
to start up only the primary packages and enable switching. The cmrecovercl command, when
run, will start up the recovery packages and enable switching during the cluster recovery operation.
CAUTION: After initial testing is complete, the cmrunpkg and cmmodpkg commands or the
equivalent options in Serviceguard Manager should never be used to start a recovery package
unless cluster recovery has already taken place.
46 Designing Continentalclusters