Backup Job - Excluding/Re-Including Disk

[jenish]

Hi all,

I’m looking for confirmation on expected Veeam behavior when excluding and later re-including the same VM disk in an existing VMware image-level backup job.

Scenario:

* VM is a Windows file server.
* Existing Veeam job backs up the VM, including the disk in question.
* We need to expand that disk beyond 16 TB.
* To do that, we need to move the data off the disk temporarily to a staging disk, reformat the original disk with a larger NTFS allocation unit size, expand it, then copy the data back.
* A temporary staging disk will be added for the data migration, but that temporary disk will remain excluded from Veeam backup.

The question is specifically about the original disk.

Possible approach:

1. Exclude the original disk from the Veeam job.
2. Let the job continue backing up the rest of the VM during the migration period.
3. Move data from original disk to temporary staging disk.
4. Reformat/expand the original disk.
5. Copy data back to the original disk.
6. Re-include the original disk in the same Veeam job.
7. Run the next scheduled backup.

What I’m trying to confirm:

When the same original VMDK is re-included in the same job, will the existing backup chain continue with a normal incremental backup, or will Veeam treat that re-included disk in a way that forces a new chain, active full, or effectively a full backup of that disk?

The concern is specifically whether the exclude/re-include action itself breaks continuity for that disk in a way that prevents the job from continuing as a normal incremental chain.

Environment:

* VMware vSphere VM
* Veeam Backup & Replication
* Image-level VM backup job
* Backup copy/SOBR/immutability are also in use downstream, so we are trying to avoid triggering a new chain or unnecessary full-size restore point if possible.

Has anyone confirmed the behavior for this exact scenario, or is there official Veeam guidance on how a previously excluded VM disk is handled when it is re-included into the same backup job? Thank you!

[Mildur]

Hi Jenish

* To do that, we need to move the data off the disk temporarily to a staging disk, reformat the original disk with a larger NTFS allocation unit size, expand it, then copy the data back.

The backup job will continue the existing backup chain. However, because the data blocks have change through the NTFS allocation unit size change and data migration, the backup job will run a full read and backup (Active Full) for all data on that volume. Any other volumes (not affected by the allocation unit size change) are still be processed incrementally.

I double checked it in my lab, the entire volume was backed up again.

Best,
Fabian