Pre-Check for update VEEAM to Version 12 using VMware

I will discus this issue with our VMware admins next week.

Inside the forum there is a workaround to change transport mode to NBD (network) - https://forums.veeam.com/post479533.html#p479533

But this is not a workaround for us - because we have a separate Backup VLAN/Network/Uplink

I created a Powershell script to Change Disk UUIDs without to reboot a vm - https://github.com/claranet/ClaranetHub/tree/main/VMware/Change-DiskUUID

Currently we test it on some vms with failed backups

Fabian ( @Mildur ) has sent an interesting VMware KB article to me:

https://kb.vmware.com/s/article/1021189

This is a possible explanation of the problem. Disks with the same UUID must not be mounted to the same VM. The Veeam backup proxys are mounting a lot of disks and there is a great chance that disks with the same UUID are among these.

Ouch! 😮

Thanks for sharing Martin..

Thanks for sharing this. Will come in handy to add to my script library.

OK, found new issue on this Problem - Backup over HotAdd will not work with “Linked Clone” as the created in vCloud Director if enabled or VM created in Virtual Desktop Environment.

Reproduce

$VM = Get-VM "<my vm>"
$Snapshot = $VM | New-Snapshot -Name "BASE"
New-VM -Name "$($VM.Name) - Linked Clone" -VM $VM -VMHost $VM.VMHost -LinkedClone -ReferenceSnapshot $Snapshot

Get-VM -Name "$($VM.Name)*"| Get-HardDisk | Select @{N='Name';E={$_.Parent.Name}}, @{N='Uuid';E={$_.ExtensionData.Backing.Uuid}}

No, I have checked our 7 U3 clusters and there are duplicate UUIDs...

I was wondering the same thing...

Answer from the support:

“In deploying vm from template they have duplicate vmdk UUID's.
This is known in vmware and at the moment there is no solution only a workaround, by deploying in same host and moving them after to different ones so no duplicates are created.
Here is where you are affected. In the past v11 did not check UUID's, it checked only moref ID's meaning that in theory you could have duplicate vddk UUID's. V12 is still checking moref id's but also UUID's in order to better handle metadata.”

Watching….

@wouter.oltlammers Yes, to be compatible with vmware they added a DiskUUID check in Version 12. The Problem on VMware side is older - and maybe it can also have some effects there.

I changed 200VMs with this script last days and Backups worked fine again.

Pleas note, if you use Network Transportmode this does not affect - It only affect if you use HotAdd-Mode.

The problem is not VMs with the same UUID, but disks with the same UUID…