Problem during Debian upgrade

Hello,

I'm facing a weird problem.

We have some Proxmox VE servers but not in any cluster.

Today, I did a Debian upgrade. Only Debian packages, we have already the 2.3.13 everywhere.

One the first server, I closed each VM ( only KVM ), did the Debian upgrade ( aptitude full-upgrade ) and reboot the physical server. I started each VM without issue.

On the second one physical server, I did the same ... but I'm unable to launch any VM ! On the left side of the web interface, I see the VM as launched, on the task windows, I've a timeout error and the SSH service of the physical server is down but ping is up. Of course, the VM did not reply on the network.

Where can I look to have more information to solve that issue without reinstalling the physical server ?

Hopefully, VM run on another physical server right now :-)

Thank for your help.

Michel