Watch out installing SP1 on your Hyper-V R2 cluster

Yesterday I spoke a customer who has problems after applying Windows 2008 R2 SP1 on his 5 node Hyper-V cluster. When validating the storage on the cluster, the following error “disk with identifier “2ef8c0……” has a persistent reservation” is displayed on multiple cluster disks.

The problem can occur in the following scenario:

**- You configure a failover cluster that has three or more nodes that are running Windows Server 2008 R2 Service Pack 1 (SP1).

  • You have cluster disks that are configured in groups other than the Available Storage group or that are used for Cluster Shared Volumes (CSV).
  • These disks are online when you run the Validate SCSI Device Vital Product Data (VPD) test or the List Potential Cluster Disks storage validation test.**

In this scenario, the Validate SCSI Device Vital Product Data (VPD) test fails. Additionally, you receive an error message that resembles the following:

Failed to get SCSI page 83h VPD descriptors for cluster disk from status 2

The List Potential Cluster Disks storage validation test may display a warning message that resembles the following:

Disk with identifier has a Persistent Reservation on it. The disk might be part of some other cluster. Removing the disk from validation set.

**A hotfix (KB 2531907) is now available that addresses the Win2008 R2 service pack 1 issue with Validate on a 3+ node cluster. You can find more information and the hotfix to download at the following link:
**KB2531907

My advice, do not install SP1 on your production Hyper-V cluster(s) till Microsoft has solution for this nasty problem!