The following limitations apply:

• ProPCV feature is supported only when the Mode value for the IMF attribute of the Application type resource is set to 3 on all nodes in the cluster.

• The ProPCV feature does not protect against concurrency in the following cases:

  • When you modify the IMFRegList attribute for the resource type.

  • When you modify any value that is part of the IMFRegList attribute for the resource type.

• If you configure the application type resource for ProPCV, consider the following:

  • If you run the process with changed order of arguments, the ProPCV feature does not prevent the execution of the process.

    For example, a single command can be run in multiple ways:

    /usr/bin/tar -c -f a.tar

    /usr/bin/tar -f a.tar -c

    The ProPCV feature works only if you run the process the same way as it is configured in the resource configuration.

  • If there are multiple ways or commands to start a process, ProPCV prevents the startup of the process only if the process is started in the way specified in the resource configuration.

• You can bring processes online outside VCS control on another node when a failover service group is auto-disabled.

  Examples are:

  • When you use the hastop -local command or the hastop -local -force command on a node.

  • When a node is detected as FAULTED after its ShutdownTimeout value has elapsed because HAD exited.

  In such situations, you can bring processes online outside VCS control on a node even if the failover service group is online on another node on which VCS engine is not running.

• Before you set ProPCV to 1 for a service group, you must ensure that none of the processes specified in the MonitorProcesses attribute or the StartProgram attribute of the application resource of the group are running on any node where the resource is offline. If an application resource lists two processes in its MonitorProcesses attribute, both processes need to be offline on all nodes in the cluster. If a node has only one process running and you set ProPCV to 1 for the group, you can still start the second process on another node because the Application agent cannot perform selective offline monitoring or online monitoring of individual processes for an application resource

• If a ProPCV-enabled service group has some application resources and some non-application type resources (that cannot be configured for ProPCV), the group can still get into concurrency violation for the non-application type resources. You can bring the non-application type resources online outside VCS control on a node when the service group is active on another node. In such cases, the concurrency violation trigger is invoked.

• When ProPCV is enabled for a group, the AMF driver prevents certain processes from starting based on the process offline registrations with the AMF driver. If a process starts whose pathname and arguments match with the registered event, and if the prevent action is set for this registered event, that process is prevented from starting. Apart from that, if the arguments match, and even if only the basename of the starting process matches with the basename of the pathname of the registered event, AMF driver prevents that process from starting

• Even with ProPCV enabled, the AMF driver can prevent only those processes from starting whose pathname and arguments match with the events registered with the AMF driver. If the same process is started in some other manner (for example, with a totally different pathname), AMF driver does not prevent the process from starting. This behavior is in line with how AMF driver works for process offline monitoring.