Read-only pass-through disk after you add the disk to a highly available VM in a Windows Server 2008 R2 SP1 failover cluster

This article provides the steps to add a pass-through disk to a highly available virtual machine (VM) in a Windows Server 2008 R2 Service Pack 1 (SP1)-based failover cluster, and helps solve the issue where the added pass-through disk status is displayed as read-only.

Applies to:   Windows Server 2008 R2 Service Pack 1
Original KB number:   2501763

Add a pass-through disk to a highly available VM

To add a pass-through disk to a highly available VM in a Windows Server 2008 R2 SP1 failover cluster, follow these steps:

  1. Log on as a domain user who is a member of the Local Administrators group on each cluster node.

  2. Configure the pass-through disk on the Storage Area Network (SAN), and map the disk to each cluster node.

  3. Open the Disk Management snap-in, and then verify that each cluster node detects the disk and that the disk status is Offline.

  4. Right-click the name of the disk, and then click Online to bring the disk online.

  5. Right-click the name of the disk, and then click Initialize Disk to initialize the disk.

  6. Right-click the name of the disk, and then click Offline to take the disk offline.

    Note

    You must take the disk offline before you add the disk to the cluster.

  7. Add the disk to the failover cluster. To do this, follow these steps:

    1. Open the Failover Cluster Manager snap-in, right-click Storage in the console tree, and then click Add disk.
    2. In the Add Disks to a Cluster dialog box, click to select the check box for the disk that you want to add, and then click OK.
    3. In the Storage pane, verify that the disk is listed in Available Storage and that the disk status is Online.
  8. Add the disk to an existing highly available VM in the cluster. To do this, follow these steps:

    1. In the Failover Cluster Manager snap-in, right-click the VM listed under Virtual Machine, and then click Settings.

    2. In the Settings dialog box, select a disk controller, and then click Add to add the disk to the disk controller. For example, click SCSI Controller, and then click Add to add the disk to the SCSI controller.

    3. In the Hard Drive pane, select the disk from the Physical hard disk list, and then click OK.

      Note

      If you cannot find the disk from the Physical hard disk list, verify that the disk status is Offline in the Disk Management snap-in.

    4. Verify that the disk is displayed under Disk Drivers of the VM. Verify that the disk is displayed in the Dependencies tab of the properties dialog box for the VM.

  9. In the Failover Cluster Manager snap-in, right-click the VM, and then click Connect.

  10. In the Disk Management snap-in, verify that the disk is added and that the disk status is Offline.

  11. Right-click the name of the disk, and then click Online to bring the disk online.

Note

You may find that the disk status is Read Only.

Resolve the issue of the read-only disk status

To resolve the issue of the Read Only disk status in the VM, follow these steps:

  1. Open a command prompt on the VM, type the net stop vds command, and then press ENTER to stop the Virtual Disk Service (VDS).
  2. At the command prompt on the VM, type the net start vds command, and then press ENTER to restart the VDS.
  3. Open the Disk Management snap-in, and verify the disk status. If the disk status is still Read Only, restart the VM.