If a failover service group comes online on more than one node, the chances of data corruption increase. You can configure failover service groups that contain application resources for prevention of concurrency violation (PCV) by setting the group's ProPCV attribute to 1.
You can set the ProPCV attribute when the service group is inactive on all the nodes or when the group is active (ONLINE, PARTIAL, or STARTING) on one node in the cluster. You cannot set the ProPCV attribute if the service group is already online on multiple nodes in the cluster. See Service group attributes.
If ProPCV is set to 1, you cannot bring online processes that are listed in the MonitorProcesses attribute or the StartProgram attribute of the application resource on any other node in the cluster. If you try to start a process that is listed in the MonitorProcesses attribute or StartProgram attribute on any other node, that process is killed before it starts. Therefore, the service group does not get into concurrency violation.