Maintenance of veritas cluster enabled app

Maintenance of a veritas cluster service group can be done as follows:

1) Execute /sbin/gabconfig -c -n1 on the active service group node
2) Modify the file /etc/gabtab on the active service group node to reflect as follows:
/sbin/gabconfig -c -n1
3) Freeze the service group by excuting, hagrp -freeze [service_group] command
4) Manually stop the service group application. Veritas cluster will detect the failure but won't perform a failover as the service group is frozen
5) Apply patch or configuration change to the application
6) Manually start the service group application. Veritas cluster will detect the availability of service group in its next monitoring cycle
7) Unfreeze the service group, hagrp -unfreeze [service_group]. Even if veritas hasn't detected the availability of app after manual startup, it won't perform a failover as it waits for the application to come up on its own. Eventually it will detect that application is already live and will update its status