When booting, Ubuntu displays an error:
The disk drive for UUID is not ready or not present yet
You have to remember the number that goes after = sign. Now boot into Ubuntu, go to terminal and sudo run blkid. The output will display UUIDs of currently mounted disks. Now sudo run editing of fstab file and study the contents. In my case, the disk was sdc while install, and when I removed the install thumbdrive, sdb was freed and the system disk became sdb. So just take the UUID of the system disk from blkid output and place it instead of the incorrect one in fstab. Save the file, reboot and the error should be gone.