Recently I restarted one of my Linux servers and the computer did not start up as expected. No external accessible service was running, like apache or SSH. This made the computer inaccessible from remote and left me in the dark. After a while, the server responded to ping, but nothing more.
After I connected the server to a display and keyboard, I could see the error message: “a start job is running for dev-disk-by […]”. After that, Linux gave me only the option to log on in rescue mode or to restart the system. A restart didn`t help. I checked the internet and found out that the message can be caused by a fstab entry.
Looking at the content of my /etc/fstab file I could see an old entry I once created for a test and never maintained (aka deleted). The system is trying to mount a partition that was not available / broken and the system stopped.
UUID=a6674495 -4249-9696-0d9c83 /mnt/disk btrfs defaults,noatime,auto 0 0
I commented out this line in fstab and restarted the system. Now the system was restarted correctly and all the services came up again.