Veeam is a pretty awesome tool for doing full VM and file-level backups of VMware vSphere VMs. Every once in a while, however, you might try to do a restore that is a bit out of the ordinary. One such scenario is when you want to do a full restore of the VMDK files (descriptor and flat) and then mounting the drive alongside the original disk on the original virtual machine. You might want to do this so you can compare files between the current copy and the restored VMDK. When you attempt to mount the restored VMDK, you will run into the following message upon reconfiguring the VM:
Message from ESX Host: Virtual disks [truncated output] have the same UUID. Virtual disks with same UUID should not be assigned to a virtual machine because duplications can lead to problems when the guest boots. Make sure virtual disks have unique UUIDs. Do you want to continue?
To avoid the duplicate UUID problem, try this: after restoring the VMDK files to your host, ssh to your ESXi server and browse to the /VMFS/Volumes/ of the restore point. Once there, run the following command against the VMDK descriptor file:
vmkfstools -J setuuid .vmdk
Replace with the name of the VMDK as seen in a directory listing of the VM’s folder in the VMFS/NFS volume or in the vSphere Client (C# or Web). This will generate and set a new (random) UUID and allow you to mount the drive to the original VM without problems!
