Microsoft has just released a hotfix for Windows Server 2008 R2 Failover Clusters where a LUN LUN that is registered to a cluster shared volume is invisible and inaccessible. The scenario is:
•You use a cluster shared volume on a Windows Server 2008 R2-based failover cluster that has the Hyper-V 2.0 role installed.
•You register a logical unit number (LUN) from the host operating system on the cluster shared volume.
•The Disk Control Manager component detects a STATUS_CONNECTION_DISCONNECTED error and starts a failover.
In this situation, Windows Server 2008 R2 does not detect the LUN.
In this situation, Windows Server 2008 R2 does not detect the LUN. This issue occurs because the Disk Control Manager component does not remap the cluster shared volume resource after a failover occurs.
A supported hotfix is available from Microsoft.