Why freeze the service group
When you freeze the service group in VCS, it will continue to monitor the resources in the cluster. But does not allow service group or the resources to be brought online or offline. Failover is also disabled during the freeze period of the service group.
The use case for the SG freeze is during a maintenance activity at database or application end. The DBA or application administrator can stop and start the database or application outside of VCS control. This will not affect the cluster and will not trigger a failover even when the resources are defined as critical.
Temporary Vs persistent Freeze
You can also specify that the freeze is in effect even if VCS is stopped and restarted throughout the cluster. When the service group is freezed temporarily and you restart the VCS cluster entirely, the SG will be unfreezed upon restart. Similarly, during a persistent service group freeze, the freeze remains in effect even when you restart the cluster entirely.
To freeze and unfreeze a service group temporarily, type:
# hagrp -freeze group # hagrp -unfreeze group
To freeze a service group persistently, you must first open the configuration and then freeze/unfreeze the cluster.
# haconf –makerw # hagrp -freeze group –persistent hagrp -unfreeze group –persistent
To determine if a service group is frozen, display the Frozen (for persistent) and TFrozen (for temporary) service group attributes for a service group.
# hagrp -value group Frozen
VCS (Infoscale Availability) : How to switch a Service Group
VCS (Infoscale Availability) : How to online and offline a Service Group