If you are like me and have a large number of VM’s on 2008 R2 and Cluster Shared Volumes requiring parrelle backups you should have a look at this hot fix
The Cluster service stops responding if you run backup applications in parallel in Windows Server 2008 R2
hand you have
- You install the Failover Clustering feature on a computer that is running Windows Server 2008 R2.
- On this computer, you run some backup applications that use Volume Shadow Copy Service (VSS) in parallel.
The hot fix addresses
This issue occurs because of a race condition between the calls of the VSS writer on the cluster. If an OnBackupShutdown method call occurs between an OnFreeze method call and an OnThaw method call, the lock on the cluster hive is not released. Therefore, a deadlock occurs, and the Cluster service stops responding.
take a look and see if it will help your environment.