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

Building a Continental Cluster
Switching to the Recovery Packages in Case of Disaster
Chapter 5250
• Halt the data sender packages running at the primary site if a
database or software data replication scheme is used, and if the data
sender package is configured for any ContinentalClusters recovery
group. In addition, the recovery command, cmrecovercl,cannot be
started until the data replicated from the primary site is properly
applied to the database, data files, or devices at the recovery site.
• If LVM and physical data replication are used, the ID of the primary
cluster is also replicated and written on the secondary devices in the
recovery site. The ID of the primary cluster must be cleared and the
ID of the recovery cluster must be written on the secondary devices
before they can be used.
If LVM exclusive-mode is used, issue the following commands from a
node in the recovery cluster on all the volume groups that are used
by the recovery packages:
# vgchange -c n <volume group name>
# vgchange -c y <volume group name>
If LVM shared-mode (SLVM) is used, from a node in the recovery
cluster, issue the following commands:
# vgchange -c n -S n <volume group name>
# vgchange -c y -S y <volume group name>
• If VxVM and physical data replication are used, the host name of a
node in the primary cluster is the host name of the last owner of the
disk group. It is also replicated and written on the secondary devices
in the recovery site. The host name of the last owner of the disk
group must be cleared out before the secondary devices can be used.
If VxVM is used, issue the following command from a node in the
recovery cluster on all the disk groups that are used by the recovery
packages:
# vxdg deport <disk group name>
Use the following command to start the failover process:
# cmrecovercl
If you have not received a notification defined in a CLUSTER_ALARM
statement in the configuration file, but you have received a
CLUSTER_ALERT and the remote site has confirmed the need to fail over,
you may override the disabled cmrecovercl command by using the -f
forcing option: