Is this a bug? I never would believe, that drive absence could cause such behavior. I don't know, when exactly it was happen, but SSD drive mounting is defined in the fstab now. Probably it was done in the OS installation process. And the system doesn't boot GUI, if I detach SSD. It rather boots in the safe mode with command prompt.
Hope, it's a bug, not feature. At least 20.04 worked fine in this aspect.
Any ideas?
Are we to assume that said SSD is not your boot device?
I too had this issue with any rev of ubuntu/debian/whatever... My solution was to edit the mount options.
UUID=a136479c-fe8d-4a35-bed4-56fd88c3c07c / ext4 noatime,defaults 0 1
UUID=3ea78b3b-f89c-40ff-a1a3-1360da43629c /mnt/server ext4 noatime,auto,nofail,errors=remount-ro,nodev,nosuid,relatime,x-systemd.device-timeout=30 0 2
Specifically the number on the end.I forget what the meaning of the numbers are, buuuut
the root partition is critical, ( 1 )
other partitions are marked as not critical, ( 2 )