Cascading Failover in a Continentalclusters, December 2005
a. Split the local mirror devices (device B’) in the secondary disk array from the primary
replication group.
b. Establish the data replication link between the local mirror devices in secondary disk
array (device B’) and the destination devices (device C) in the recovery disk array
(i.e. establish the recovery replication group).
c. Check the data synchronization process and wait until synchronization completes.
d. Once the synchronization completes, split the data replication link between the
secondary disk array and the recovery disk array (i.e. the recovery replication
group).
e. Establish the local mirror devices (device C’) in the recovery disk array as mirrors of
the standard devices.
f. Re-establish the local mirror devices (device B’) to the primary replication group as a
mirror of the standard device.
4. LVM requires to import volume group information. Please follow LVM specific commands to
configuration volume groups on all the nodes that are connected to the disk arrays.
Before Serviceguard and Continentalclusters can be configured, the created volume groups must work
properly on all nodes in connected to the disk arrays. Please refer to the specific volume group
management documentation for procedure for importing and activating the volume group on a given
node.
Data Initialization
If there is already a metropolitan cluster with the data replication already established with a local
mirror configured for rolling disasters and you are now adding Continentalclusters into the
configuration (that is adding a recovery site with a recovery disk array), only procedure 2 is required.
Procedure 1: Mirroring from the Primary to the Secondary Disk Array
This procedure is illustrated in Figure 2.
Figure 2 - Mirroring from the Primary to the Secondary Disk Array
Execute the following steps:
1. Establish mirroring of the secondary device (device B) to the local mirror device (device B’) in
the secondary disk array.
2. Establish replication of the primary replication group which is between the primary site and
the secondary site in the primary cluster.
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