How to Disable Undo Disks for a Virtual Machine
Applies To: Virtual Machine Manager 2008, Virtual Machine Manager 2008 R2, Virtual Machine Manager 2008 R2 SP1
In Microsoft Virtual Server, undo disks are used to return a virtual machine to a previous state. In Virtual Machine Manager (VMM), undo disks are not supported and checkpoints are used instead to restore a virtual machine to a previous state. When you add an existing Virtual Server virtual machine host to VMM, virtual machines on the host with undo disks have Unsupported Undo Disk status until you disable the undo disks. If an undo disk is created on a virtual machine by using the Virtual Server Administrative Website after the host has been added to VMM, the virtual machine will have an Unsupported Undo Disk status until you disable the undo disks.
When you disable undo disks, you can either merge the undo disks into the virtual machine or discard them so that the virtual machine can be operated and managed in VMM.
To disable undo disks for a virtual machine
In Virtual Machines view, in the navigation pane, navigate to the host on which the virtual machine is deployed.
Click a virtual machine that has an Unsupported Undo Disk status, and the in the Actions pane, click Disable undo disks.
A prompt displays indicating that VMM must shut down the virtual machine in order to disable its undo disks.
In the message box, click Yes to continue.
In the Disable Undo Disks dialog box, do one of the following:
Click Merge to incorporate the changes in the undo disks into the parent virtual hard disk so that the virtual machine retains its most current state.
Click Discard to discard the undo disks without saving the changes to the virtual hard disks.