Disaster recovery rehearsal in Continentalclusters

11
Rehearsal package configuration
Rehearsal of a recovery group starts the rehearsal package, which is configured with the recovery
package’s volume group/filesystem directory. The rehearsal package is a non-Metrocluster type
package (i.e., the Metrocluster environment file is not present in the package directory) with its own
package directory containing a separate copy of the configuration and control files.
When the rehearsal package is started, the volume group/filesystem that is usually activated during
a recovery will be activated. Also, by configuring the rehearsal package with the application, i.e.,
configured in the recovery package, the application installation and its access to the data can be
verified. The cmrecovercl option {-r –g <recovery group>} is used to start rehearsal for a recovery
group on the recovery cluster.
Rehearsal package is configured on all recovery cluster nodes on which recovery package is
configured. It is a mandatory requirement that the rehearsal package be configured to share the same
the volume group and file system mount point that is configured for the recovery package. By using
the recovery package volume group, the rehearsal verifies the volume manager infrastructure that is
used in an actual recovery. Also by using the same volume group, the rehearsal application (which
could be the same application that was packaged with the recovery package) will have read-write
access to the secondary mirror copy.
Similarly, by using the same file system mount points, the application setup and configuration used
for the recovery can also be used for the rehearsal without reconfiguration. To prevent split-brain
scenarios, it is recommended that the rehearsal package be configured with an IP address that is
different from the one configured for the recovery package. See Figure 2 for a pictorial representation
that compares recovery and rehearsal package configuration.
Figure 2: Comparing recovery and rehearsal package configurations
Caution: It is the user's responsibility to ensure that the rehearsal package is configured to use the recovery package’s
volume group and file systems directory and also that the IP address is different.
Physical
storage
[VG = oraVG, FS
= /oradata]
Service IP
address
Rehearsal package
configuration
Recovery package
configuration
[IP address =
“Production IP”
Volume
group, file
system
[Disk = oraDisk]
[VG = oraVG, FS
= /oradata]
[Disk = oraDisk]
[IP address = “non
Production IP”