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P2V Restore to Proxmox - Error output: MAX vcpus allowed Veeam Backup and Replication


Hi, 

 

I do a Backup from a Phyiscal Maschine and try do restore it by Veeam Backup and Replication. 

Of course the PMaschine has 8 Cores, the proxmox SVR just have 4 Cores. 

I got the error message “Failed to reach the hypervisor. Error output: MAX 4 vcpus allowed”. Is there any solution? I have no possibility to change the vm config bevore create.  Thanks for any help.

8 comments

Tommy O'Shea
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  • Veeam Legend
  • 343 comments
  • March 30, 2025

I am not aware of any way to have Veeam create a VM with custom virtual hardware. As far as I am aware, it will automatically create it as close to the original server as possible.

What you can do instead is create a VM with the virtual hardware you require (Make sure the disks are slightly larger than the original server), attach the Veeam Recovery Media created by the agent, then perform a Bare Metal Recovery to within the OS of that VM.


Chris.Childerhose
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  • Veeam Legend, Veeam Vanguard
  • 9535 comments
  • March 30, 2025

Creating the VM in Proxmox and using the restore media seems to be the way to go here as there was another post on the community with the same issue and this was the answer.

https://community.veeam.com/discussion-boards-66/restore-vm-to-proxmox-ve-3721

 


  • Author
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  • 1 comment
  • March 30, 2025

Thank you! Thats exactly what i dont want to do … I want just use the function from veeam .. .restore to proxmox … like restore to vmware esxi… maybe somebody have a solution.


Chris.Childerhose
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  • Veeam Legend, Veeam Vanguard
  • 9535 comments
  • March 30, 2025
Rob.Die wrote:

Thank you! Thats exactly what i dont want to do … I want just use the function from veeam .. .restore to proxmox … like restore to vmware esxi… maybe somebody have a solution.

Since you cannot change the VM specifications there will not be and you will continue to have the issue. Only other option is via a support ticket to see if they have any workaround for it.


Tommy O'Shea
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  • 343 comments
  • March 30, 2025

I found this guide for migrating from VMware to proxmox.

In it, it mentions "It is possible, (though not recommended) to override that limit by editing the QemuServer.pm file (look for $allowed_vcpus)."

If you feel comfortable doing so, you may be able to get proxmox to allow more CPUs this way. I'm sure you'd want to reset that setting after your migration to be safe. 

 

Aside from that, it seems like a bug in the Veeam restore logic that it doesn't check that value before restoring and restore with less vcpus. Perhaps a feature request or support ticket would be in order. 


I created a Powershell script to change the Metadata of the VBM Backupfile in order to change CPU or RAM Settings, as i could not restore a physical server to a vm on a Proxmox Host, which had less ressources as the original backed up server.

https://github.com/mrburner1973/VeeamP2VProxmox


Chris.Childerhose
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  • 9535 comments
  • July 29, 2025
mrburner1973 wrote:

I created a Powershell script to change the Metadata of the VBM Backupfile in order to change CPU or RAM Settings, as i could not restore a physical server to a vm on a Proxmox Host, which had less ressources as the original backed up server.

https://github.com/mrburner1973/VeeamP2VProxmox

Thanks for sharing this with the community.  Great work. 👍


Tommy O'Shea
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  • Veeam Legend
  • 343 comments
  • July 29, 2025

@Rob.Die, check out the reply from ​@mrburner1973 and the script included within. It looks like a much better suggestion than mine; Modifying the backup metadata file to restore the vm with less resources, rather than changing the proxmox server’s maximums, which could cause issues down the road.

If you’re able, please also select a comment as “Best Answer” to close out this question post.


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