Proxmox Version 9 Linux VM Backup / Restore fail

[homerjs]

[UPDATE] Official Proxmox V9 support for Veeam Backup & Replication 12.3.2 is available with the latest plug-in version that can be downloaded here > https://www.veeam.com/kb4775

After upgrade from PVE 8 to 9 , only VMs with Linux (Ubuntu) fail to Backup and fail to Restore.
VM with WIndows is working good.
Backup Log : 06.08.2025 20:42:11 :: ALVAULT01 : Failed to perform backup: Failed to map disks
???

[homerjs]

Workaraound:
Liunx VM , change Hardware > Machine from Default(i440fx) to I440fx Version 9.2
it works

[Mildur]

Hi Homer,

Welcome to our forum.

Please note that for future posts about technical issues, this is not a support forum, as explained in the forum rules displayed when you click New Topic. If you encounter a technical problem, please contact our customer support team first.

Regarding your issue, I'm glad you found a solution. However, I’d like to point out that Proxmox v9 was released only a few days ago. Our general goal is to provide official support for a new version within 90 days after GA. We cannot guarantee at this time that Proxmox 9 is fully compatible with the current build of Veeam Backup & Replication.

For future Proxmox major updates (10, 11, 12, ...), I recommend waiting until we explicitly mention support for the new version in our Help Center. Otherwise, you may risk being without backups for weeks or even months, unless you redeploy a previously supported Proxmox version.

Best regards,
Fabian

[Gostev]

Simply put, Proxmox v9 if not yet supported. To the point where we can't guarantee that "successful" backups following your fix are actually recoverable. Adding this just to be sure future readers don't read the workaround posted by homerjs as the magic solution that enables Proxmox 9 support.

[gergo.kerekes]

Workaraound:
Liunx VM , change Hardware > Machine from Default(i440fx) to I440fx Version 9.2
it works

Confirmed! It works!

Thank you!

[NuAngel]

I saw another thread talking about restore failures, and how switching the machine type to i440fx 9.2 solved their issue, but I've had no such luck.

I also understand that there may not be full support for ProxMox 9.x for at least 90 days as it is still a relatively "hot off the presses" release. But I'm hoping that in the intervening 40-ish days since the other thread was started, someone might have some advice for me, so I wanted to created this post!

Upon deployment, the Proxmox worker / Proxy device is created by Veeam and boots up / updates just fine (although I did note a bug with that assigning the wrong number of cores/threads {should I make that its own thread?}). However, when I try to run a backup, all of my VMs, whether they are Windows or Linux guests, all report "Failed to perform backup: Failed to map disks."
[*]It then says "Backing up the VM xxx in the 'HotAdd' mode'
[*]Then reports that the worker was shutdown successfully.

No backup is created. These VMs are stored on a ZFS3 pool, is the difficulty Veeam being able to read ZFS?

I will note: the machine type created by this version of Veeam / Proxmox is a q35 machine, not an i440fx. Changing the machine type to i440fx, even changing the version to 9.2, or 9.2+pve1 and or changing the BIOS to SeaBIOS from OVMF (UEFI), etc... no changes to the 'hardware' of the VeeamWorker in Proxmox seemed to (if anything the backup didn't even get as far).

Sorry for a bit of word-vomit, but I'm open to any tips or suggestions?

[keithlammers]

I think that you'll likely have to wait for official Veeam support. For that workaround to work, the target VM's machine version needs to be 9.2, but Veeam creates the target VM with the latest machine version, which is 10.0 on Proxmox 9, so Veeam can't hotadd the disks on the target VM for restore. I tried to change the target VM's machine version as soon as Veeam creates it, but Proxmox has the configuration locked while Veeam is creating it and then Veeam fails before it's possible to change it, so no luck there.

[keithlammers]

Update to my last reply. I had mistaken your issue for restore issues vs backup issues. Backing up works if you change the machine version to 9.2 for the VM you're backing up. Leaving the proxy VM at q35 latest seems to work fine as long as the VM that's being backed up is set to machine version 9.2.

Restores of the backed up VM seem to work here as well. I ran into restore issues when trying to restore from a Hyper-V backup to a Proxmox 9 server. In that case, Veeam creates the VM with machine version 10.0 and then can't hotadd the disks for restore.

But as gostev mentioned, if this is a production environment, it's best not to rely on this workaround, as it's not supported and could leave you stranded.

[Gostev]

All we're very close to releasing the official support, just a few more days before it ships.

[NezzerGetti]

Well isen't that wonderful news @Gostev!

Care to share if there is any restore issues in the new version that you are fixing?
I'm trying out PVE9 and all is working(with machinetype fix for the vm) but I get really slow restore speed (200-265mbit). Backups are running superfast.
Very simular to this thread but I see no resolution on it: kvm-rhv-olvm-pve-schc-f62/my-actual-summary-t78724.html

Maybe I need another thread ,you decide

[rovshan.pashayev]

Good news everyone,

Proxmox VE v9 is now officially supported with the new version 12.1.5.17 of Veeam Plug-in for Proxmox VE.

Please refer to KB4775 for further details.

Cheers

[NezzerGetti]

Well isen't that wonderful news @Gostev!

Care to share if there is any restore issues in the new version that you are fixing?
I'm trying out PVE9 and all is working(with machinetype fix for the vm) but I get really slow restore speed (200-265mbit). Backups are running superfast.
Very simular to this thread but I see no resolution on it: kvm-rhv-olvm-pve-schc-f62/my-actual-summary-t78724.html

Maybe I need another thread ,you decide

This issue has been resolved in latest PVE plugin.
If anyone else is stuck

[keithlammers]

Can confirm here that PVE plugin 12.1.5.17 fixed the issue for me as well. I love that support for hypervisors is done via plugins so that you are able to release updates to them without a full Veeam release. Thanks guys!

[NuAngel]

Good news everyone,

Proxmox VE v9 is now officially supported with the new version 12.1.5.17 of Veeam Plug-in for Proxmox VE.

Please refer to KB4775 for further details.

Cheers

Installed PVEPlugin_12.1.5.17 to Veeam B&R 12.3.2.3617.

Added PVE9.0.10 servers to Veeam Virtual infrastructure. Deploying new workers to both. Deployment went seamlessly, no showstopping behaviors.

Initial test backups appear to be successful. I haven't done a full restore, yet, however I did perform a "Guest File Restore" and was able to successfully browse the backup I had created, so that's a good sign.

Great work so far!

--Two things:
1. [Existing] Bug: If you deploy, for example, with 8 "CPUs" it will assign 8 Sockets and 1 core.
2. [Feature request]: Is there any way to query ProxMox for the MAC address of the WORKER device and display it to the user before the first boot, then adding a "continue to first boot" button (or something similar?). Would be more convenient for those of us trying to have a static IP reservation in our DHCP server ready to go before the Worker tries to obtain an IP.

[rovshan.pashayev]

Hello Garrett,

Thank you for your feedback—your requests have been noted!

[Manfriday]

I applied the new PVE plugin and I am pretty sure it made things worse in our environment.
Before I was getting a few machines that were failures but after the PVE plugin was updated the majority of my backups are failing with 'Failed to perform backup: Failed to map disks'

I have a ticket open (07834202). hopefully its something simple I missed.

[anpa]

@manfriday - I was using the new plugin version with PVE8, worked great. Just upgraded to PVE9, and I get the same error. Running all my VMs on Ceph storage, so hyperconverged storage. Could be something with my VBR (12.3.1.1139), so thought I'd mention it here so you know you're not alone

[Manfriday]

Thank you for chiming in.
Most of my backups have blown up. Seems to be affecting more linux machines than windows, but havent yet confirmed that to be 100% true across the board.
Open a ticket and reference my own ticket. Maybe both of our issues will get escalated more quickly.
Support guy I am talking to now suggested I change all of the VM configs to use Machine Version 8.2.
I really dont want to do that to 900+ VMs when this is supposed to be supported.

[karsten123]

VBR 12.3.2 is required! are you both on 12.3.1?
kb4775

[Regnor]

Can you try to reboot one of the affected virtual machines and try to create a backup afterwards?

[anpa]

@karsten123 - yes, since upgrading to 12.3.2 does not work at the moment, but that may be due to me installing the proxmox plugin then.. =) This is my lab, so only running community edition =)

@Manfriday - same here, mostly Linux that have issues.

@Regnor - will try that as well.

[Manfriday]

I am on 12.3.2.

It is looking like the reboot of the VMs resolves the issue.
I'm curious as to why that would be? I could see a power off/on twiddling a bit in the vm config, but a simple reboot seems very OS-centric, and it surprises me that it resolves it.

Looks like I need to schedule reboots for 864 machines, which is a drag, but at least there is a resolution.

[Manfriday]

Minor update:

It looks like issuing the reboot command from inside the guest OS does NOT fix the issue.
You have to issue the reboot command from the Proxmox GUI by individually right-clicking the VM and selecting "reboot".

So again, this makes me wonder what is going on behind the scenes, and if there is another way to achieve the 'fix' other than right-click rebooting each of over 800 VMs individually.

[Regnor]

The issue could be related to the upgrade of the virtual machine version which requires a hard reboot/reset. I received this feedback on Reddit but you can work together with our support to see if there's any other solution or approach Proxmox directly.

[anpa]

Update from me as well.

Uninstalling latest PVE plugin enabled the upgrade from 12.3.1 to 12.3.2, so that was good. Strange that I could install the plugin on an incompatible version, I thought it would have said something about it during the install process.
Two VMs worked great after issuing the "Reboot" command via Proxmox. After this I tried to shut down and start a few other VMs, and the result was the same - backups works again.

[NuAngel]

Interesting situation I'll update on tomorrow but wanted to note here:

• Created a backup job with several VMs, but did not run it yet.
• Edited the backup job to add a new VM, and it showed 2 of my 6 VMs grayed out and when I went to click next it prompted me that those machines were "missing from virtual infrastructure."
• One Ubuntu 24.04, one Windows 10.
• Can confirm that the mentioned VMs are not only still present in the Proxmox cluster, they are running on their preferred nodes, they are started, and they are working just fine.
• Running the first "Active Full" backup of the job now.
• Will report in the morning if those two machines succeeded or failed.

[Gostev]

I'm locking this thread now that the original question has been answered and the topic is quickly becoming a mess of unrelated posts.

Official Proxmox V9 support for Veeam Backup & Replication 12.3.2 is available with the latest plug-in version that can be downloaded here > https://www.veeam.com/kb4775

If you experience any sort of technical issues, please always start from opening a support case as opposed to posting on the forums. This way we can avoid thrashing the forum with environment-specific issues while allowing PMs to focus on discussing and resolving the real product bugs (as opposed to being DDOSed with environmental issues).

A friendly reminder of the forum rules. They are displayed in red font every time you post, please don't just ignore them.