I have proxmox installed. Everything works fine- few systems there. At some point I have added new SSD disk via USB - mainly to have it for NAS purpose. However when remove this disc from NUC proxmox cannot start anylonger... any idea what to do?
If you add that USB SSD to your fstab it needs to be connected in order to boot. Otherwise PVE will fail because the SSD can't be found. If you don`t want to have that USB SSD permanently attached to the system, you should manually mount and unmount it and not automatic via fstab.
So either add that SSD again or remove the line from your fstab to be able to boot again.