Getting "a start job is running for dev-disk-by.."
followed by a 90 second delay during each boot.
This occurred to me once when I repartitioned my hard drive and relocated my swap file.
This is caused by an incorrect UUID entry on your /etc/fstab file because it is still referring to the old swap.
To fix this, you have to check the correct UUID that you're currently using:
$ sudo blkid
Now open your fstab file and inspect any difference in values and replace them with the correct one accordingly.
$ sudo gedit /etc/fstab
After editing the file, go ahead and save it then reboot your computer.
Hope this helps!