When performing a failover or attempting to bring Volumes and Disks offline within a Veritas Cluster Server (VCS) clustered environment, VCS will require a lock be placed on the volumes in order to manipulate the behavior of the Volumes / Disks and perform the requested tasks. In certain circumstances, there may be an issue with the ability for VCS to obtain the volume lock. Some of these circumstances, and how to counteract them, are listed below. These are just some examples of different applications and hardware items that can prevent volume lock by the cluster.
Unable to Lock Volume Errors (Windows Error = 5)
MountV/Mount resources can hang on offline or online if it detects an open handle to the volume. This can be caused by numerous issues including:
1. Process or application that is connected to the disk. For example, having an Explorer window open to the volume.
2. Monitoring software including:
a. Compaq Insight Manager
b. HP OpenView
c. IBM Director
d. CA Unicenter
e. Microsoft Operations Manager (MOM)
f. Dell OpenManage
g. IBM RAID Director
The ForceUnmount and AutoFSClean (MountV/Mount attributes being enabled) can be used to force a dismount of the drive. Unmounting a drive is the process of removing the drive letter, making it unavailable to the operating system.
ForceUnmount and AutoFSClean are not recommended to be used if a database application (e.g. Exchange, SQL) is involved. If a volume is forcefully unmounted, AutoFSClean runs a checkdsk /x. Data corruption is a possibility. If AutoFSClean is not enabled and there is an issue, the volume will not mount as the file system shows as dirty.
Utilities such as OH.exe (Windows 2000 Resource Kit) or Handle.exe from Microsoft can be used to find out which application is placing a handle on the volume. These utilities are maintained by Microsoft. Please review their documentation for details regarding these utilities.
The WMI service may show up as the culprit but many applications use WMI to access the resources to be monitored. If the WMI service is deemed as a problem it should be disabled temporarily to see what other controlling service may be the actual culprit.
In some instance, if there is a DiskKeeper Service being used on the server, this can cause an open handle to be present on the volume, causing the MountV resource to not come offline correctly. Should this be the case, a simple test would be to shut down the DiskKeeper service and test the ability to offline the MountV resource. Contact DiskKepper vendor so they may advised how to avoid application creating open handles on volumes.