Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Physical Data Replication for ContinentalClusters Using Continuous Access XP
Failback Scenarios
Chapter 6 317
3. Start the cluster at the primary site. Assuming they have been
properly configured, the ContinentalClusters primary packages
should not start. The monitor package should start automatically.
4. Manually start the ContinentalClusters primary packages at the
primary site using the command
# cmrunpkg <pkg_name>
The CAXP integration script is programmed to handle this case.
5. Ensure that the monitor packages at the primary and recovery sites
are running.
Scenario 3
The primary site has lost power, including backup power (UPS), to both
the systems and disk arrays that make up the MC/ServiceGuard Cluster
at the primary site. There is no loss of data on either the XP disk array
or the operating systems of the hosts at the primary site. The system
administrator desires to switch the identities of the two sites (i.e., the old
or original primary site will become the recovery site and the old or
original recovery site will become the primary site).
Failback in Scenario 3
After reception of the ContinentalClusters alerts and alarm, the
administrators at the recovery site follow the prescribed processes and
recovery procedures to start the protected applications on the recovery
cluster. Each ContinentalClusters package control script will evaluate
the status of the XP paired volumes. Since neither the systems nor the
XP disk array at the primary site are accessible, the control file will
initially report the paired volumes with a local status of SVOL_PAIR or
SVOL_PSUE and a remote status of EX_ENORMT, PSUE or PSUS, indicating
that there is an error accessing the primary site. The CAXP integration
script is programmed to handle this condition and will enable the volume
groups, mount the logical volumes, assign floating IP addresses and start
any processes as coded into the script. The fence level of the paired
volume, either NEVER, ASYNC, or DATA, will not impact the starting of the
packages at the recovery site. The CAXP integration script will perform
the following command with regards to the paired volume:
# horctakeover -g <dev-grp-name> -S