Migrating large VM from one host to another with Quick Migration

[importantchicken562]

Hi all,

I have a single-host vSphere environment with a large VM (~5TB) that's backed up nightly via Veeam B&R. I need to migrate this VM to a new host, and my plan was to use Veeam's Quick Migration feature.

My main concern is avoiding a new full backup after the move. I ran a test: shut the VM down, performed a Quick Migration, and left the "delete VM from source host" box unchecked — I wanted the option to boot the original VM again if the migrated copy didn't come up cleanly. But because I left that box unchecked, Veeam treated the VM on the new host as a brand-new object and kicked off a full backup instead of continuing the incremental chain.

What I actually need is a way to move the VM to the new host while Veeam still recognizes it as the same VM and continues backups from where the last one left off — ideally without losing my safety net of being able to fall back to the original VM if something goes wrong.

Has anyone dealt with this? Any advice on how to preserve the backup chain through a host migration like this would be appreciated.

[vnikiforov]

Hello, Mark,

Quick Migration is a correct tool to use here. The procedure is as follows: the source VM is powered on when the migration starts, VMware Tools are running inside it, and you select the Delete source VM files upon successful migration check box. Veeam then waits for a heartbeat from the VM on the target host, updates the VM ID in its database, and switches all backup jobs to the new VM. The next run is incremental. See the last step of the Quick Migration wizard for the exact behavior.
Your test didn't follow two of those conditions: you powered the VM off and left the check box cleared, so the jobs kept tracking the source VM and the copy on the new host became a new object.
(since we use MOrefs - vmware's managed object reference to track VMs on a new host that's absolutely new IDs)

As for the safety net, Veeam deletes the source VM files only after it receives that heartbeat, so a copy that never boots does not remove your original. Your nightly backups cover the rest - if anything goes wrong after the switch, restore the VM from the latest restore point.

[importantchicken562]

Thanks. Do I need to update the VMWare Tools on the source VM at all before I start? I am asking because I am moving the VM from a host running VSphere 7 to Vsphere 8.