Building Disaster Recovery Serviceguard Solutions Using Continentalclusters for Linux B.01.00.00

Restore replication environment for recovery

First, synchronize the secondary mirror copy with the primary mirror copy and then synchronize

the BC with the secondary mirror copy.

# pairresync –g <device_group>

# export HORCC_MRCF=1

# pairresync –g <device_group>

# unset HORCC_MRCF

Move the recovery group out of maintenance mode

After the rehearsal operations are completed, the recovery groups must be taken out of maintenance

mode. If not, an actual recovery using the cmrecovercl command might fail to start up the

recovery packages in the recovery groups.

# cmrecovercl –e -g <recovery_group_name>

Run the cmviewconcl command to verify that the recovery group is not in maintenance mode.

# cmviewconcl -v

Cleanup of secondary mirror copy

After the rehearsal is completed and before the recovery groups are moved out of maintenance

mode, the operator must ensure that the rehearsal changes on the secondary mirror copy are

cleaned up.

During rehearsal, the rehearsal application will have invalidated the secondary mirror copy with

non-production I/O. Hence, before moving the recovery group out of maintenance, the operator

must clean up the secondary mirror copy by synchronizing it with the primary mirror copy or

restoring from the BC (in case the primary cluster fails during rehearsal). If not, recovery (via

cmrecovercl) or recovery package startup via the cmrunpkg and cmmodpkg commands must

potentially start up the recovery package on data invalidated by rehearsal.

Recovering the primary cluster disaster during DR Rehearsal

In case of a disaster at the primary cluster while performing DR Rehearsal, follow the below steps

to recover the application at the recovery cluster:

• Halt the rehearsal package.

# cmhaltpkg <rehearsal_package_name>

• Restore the recovery cluster data using the BC.

# export HORCC_MRCF=1

# pairresync -restore –g <device_group> -I <instance_no>

# unset HORCC_MRCF

• Move the recovery group out of maintenance mode

# cmrecovercl –e -g <recovery_group_name>

• Run cmrrcovercl command.

# cmrecovercl

Limitations of DR rehearsal feature

Following are the limitations of the DR rehearsal feature:

36 Disaster recovery rehearsal in Continentalclusters