There are a number of restrictions that you should be aware
of if you are planning to deploy multiple HADR standby databases.
The restrictions are as follows:
- You can have a maximum of three standby
databases: one principal standby and up to two auxiliary standbys.
The exception is for DB2® pureScale® environments,
in which you can only have one standby (the principal standby).
- Only the principal standby supports all
the HADR synchronization modes; all auxiliary standbys will be in
SUPERASYNC mode. The exception is for DB2 pureScale environments,
in which the principal standby can only be in ASYNC or SUPERASYNC
mode.
- IBM® Tivoli® System Automation for
Multiplatforms (SA MP) support
applies only between the primary HADR database and its principal standby.
The exception is for DB2 pureScale environments,
in which SA
MP only
manages the local cluster and does not automate failover to the standby
cluster
- The hadr_target_list database configuration
parameter must be set on all the databases in the multiple standby
setup. Each standby must include the primary in its hadr_target_list setting.
DB2 10.5 for Linux, UNIX, and Windows