Home Assistant OS 6.6 does not start properly after reboot

I have a Home Assistant instance which was running rock solid for the last couple of years.
It runs on Home Assistant OS 6.6 which runs in a VM under Proxmox.

After a reboot yesterday, Home Assistant OS 6.6 boots and starts just until the point the Container Engine starts, then there is some error (which I can’t see, because the message scrolls away too fast) which makes the OS to enter the reboot state. It then shuts down properly…

How would I go to diagnose this? I’ve mounted the Home Assistant disks from Proxmox, but I can’t find any boot logs, so I am not even sure what the error is…

Thanks for any help!

I have problems with OS 6 +. If possible go to a earlier backup and then upgrade again it should go to OS 7.

This was the fastest way I fixed it

In the meantime, I have found the issue with my system. Some integration was “spamming” the home assistant logs (multiple GBs) and that took all of the available disk space.

Still, I’d be interested in where to find the boot log messages of Home Assistant OS.