Taking Snapshots of Virtual Machines With Virtual Disks on Different Datastores Can Cause Datastores to Disappear From the VI Client

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

When a virtual machine is attached to two or more virtual disks (.vmdk files) where the disks are not on the same datastore and a snapshot is taken of the virtual machine (VM), a datastore might disappear from the Virtual Infrastructure (VI) Client for that VM and other snapshot functionality might break. For example, one possible scenario is that there is a VM with two .vmdk files, one on datastore1 where the .vmx file is also located and one on datastore2. When the snapshot is initiated, datastore2 disappears from the Virtual Infrastructure client view for that VM and you will be unable to delete the snapshot from that VM.

Environment

VMware VirtualCenter 2.0.x
VMware Consolidated Backup 1.0.x

Resolution

This is a known issue for ESX Server 3.0.1, VMware Consolidated Backup 1.0.2, <?xml:namespace prefix = st1 /><st1:place w:st="on"><st1:placename w:st="on">Virtual</st1:placename> <st1:placetype w:st="on">Center</st1:placetype></st1:place> 2.0.1 and all earlier versions of these products. The issue will be fixed in later versions of these products.

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This problem is not seen when the .vmdk files and .vmx are located on the same datastore. To work around this problem, move all .vmdk files onto the datastore on which the .vmx file (the virtual machine configuration file) is located before taking snapshots. The .vmdk files have to be renamed with vmkfstools –E before they can be moved to the same datastore.

Follow this procedure to rename one of the disks:

1. Make sure no snapshots of the virtual machine exist.

   Note: If your virtual machine already has a snapshot, power off the virtual machine and delete the snapshot.

2. Power off the virtual machine.

3. Detach from the virtual machine the disk you plan to move, but do not delete the disk.

4. Log into the ESX Server system and use the following command to rename the disk:

   vmkfstools -E <old_name> <new_name>

   For example, to rename the disk foo.vmdk to bar.vmdk, enter vmkfstools -E foo.vmdk bar.vmdk.

5. From the VirtualCenter user interface (UI), add the renamed disk back to the virtual machine.