Hi everyone,I'm trying to determine whether this is a bug or if I'm missing something in my configuration.EnvironmentVeeam Backup & Replication Community Edition 13 Build: 13.0.2.29 Proxmox VE 9.2.2 2-node Proxmox cluster Shared QCOW2 storage Backup Proxy/Worker successfully deployed HotAdd transport modeProblemAll Windows VMs are backed up successfully.Any Linux/BSD VM fails with: Failed to perform backup.Failed to prepare disks for backup.So far I have reproduced the issue with:Debian 13 (fresh installation) pfSenseWindows Server VMs work without any issues.What I have already testedCreated a brand new Debian VM → same error Manual snapshot from Proxmox → works Snapshot through Proxmox API (pvesh) → works qemu-img check → no corruption Guest Processing disabled Inventory rescanned Worker redeployed VM migrated between nodes Same storage used by both Windows and Linux VMs Windows backup succeeds using the same repository and proxyExample:pvesh create /nodes/nodo2/qemu/108/snapshot --snapname veeam-testskipping guest filesystem freeze - disabled in VM optionssnapshotting 'drive-virtio0'internal qemu snapshotSo snapshots are working correctly.ObservationThe job reaches HotAdd mode before failing.The failure occurs during "Prepare disks for backup", not while creating the snapshot.This makes me think the issue is happening after snapshot creation, during disk preparation or attachment.QuestionsHas anyone experienced this with Proxmox 9.2.x? Is this a known issue with Veeam 13.0.2.29? Is there any debug logging specifically for the "Prepare disks for backup" phase? Is there anything else I should check on the worker or Proxmox side?Any ideas would be greatly appreciated.Thank you.

Question

Veeam 13.0.2.29 + Proxmox 9.2.2 - "Failed to prepare disks for backup" only on Linux/BSD VMs

Forum|Forum|9 days ago
July 31, 2026
4 comments
57 views

M

marilia.clement
Not a newbie anymore

Hi everyone,

I'm trying to determine whether this is a bug or if I'm missing something in my configuration.

Environment

Veeam Backup & Replication Community Edition 13
Build: 13.0.2.29
Proxmox VE 9.2.2
2-node Proxmox cluster
Shared QCOW2 storage
Backup Proxy/Worker successfully deployed
HotAdd transport mode

Problem

All Windows VMs are backed up successfully.

Any Linux/BSD VM fails with:

Failed to perform backup.
Failed to prepare disks for backup.

So far I have reproduced the issue with:

Debian 13 (fresh installation)
pfSense

Windows Server VMs work without any issues.

What I have already tested

Created a brand new Debian VM → same error
Manual snapshot from Proxmox → works
Snapshot through Proxmox API (pvesh) → works
qemu-img check → no corruption
Guest Processing disabled
Inventory rescanned
Worker redeployed
VM migrated between nodes
Same storage used by both Windows and Linux VMs
Windows backup succeeds using the same repository and proxy

Example:

pvesh create /nodes/nodo2/qemu/108/snapshot --snapname veeam-test

skipping guest filesystem freeze - disabled in VM options
snapshotting 'drive-virtio0'
internal qemu snapshot

So snapshots are working correctly.

Observation

The job reaches HotAdd mode before failing.

The failure occurs during "Prepare disks for backup", not while creating the snapshot.

This makes me think the issue is happening after snapshot creation, during disk preparation or attachment.

Questions

Has anyone experienced this with Proxmox 9.2.x?
Is this a known issue with Veeam 13.0.2.29?
Is there any debug logging specifically for the "Prepare disks for backup" phase?
Is there anything else I should check on the worker or Proxmox side?

Any ideas would be greatly appreciated.

Thank you.

+23

coolsport00
Veeam Legend
Forum|Forum|9 days ago
July 31, 2026

I’ve not heard this issue arise to this point yet @marilia.clement . You could look at the Logs in C:\ProgramData\Veeam\Backup\<job-name>.log to see if it has better details on what the issue could be, or you can reach out to Support...which is your best bet.

Shane Williford - Veeam VMCA/VMCE+ | Veeam Legend | VUG Leader | VCP-DCV | Twitter: @coolsport00

Like

M

marilia.clement
Author
Not a newbie anymore
Forum|Forum|9 days ago
July 31, 2026

I’ve not heard this issue arise to this point yet @marilia.clement . You could look at the Logs in C:\ProgramData\Veeam\Backup\<job-name>.log to see if it has better details on what the issue could be, or you can reach out to Support...which is your best bet.

Thanks for your reply.

I already checked the logs under C:\ProgramData\Veeam\Backup, including the job logs, but unfortunately there isn't any additional information. The logs simply end with "Failed to prepare disks for backup", without any detailed exception explaining why the preparation failed.

So far I've also verified the following:

Manual snapshots work correctly.
Snapshots created through the Proxmox API (pvesh) also work correctly.
Windows VMs back up successfully.
A brand new Debian 13 VM fails with the same error.
pfSense fails with the same error.
qemu-img check reports no corruption.
Guest Processing is disabled.
Workers were redeployed and tested successfully.

At this point, I'm trying to determine whether this is a known issue with Veeam 13 and Proxmox VE 9.x or if there is a way to enable more verbose logging specifically for the "Prepare disks for backup" stage.

Unfortunately, I'm using the Community Edition, so opening a support case isn't an option.