fstab is a file (actually /etc/fstab) showing the partitions that are automatically mounted by the kernel when it is booted. The kernel reads the fstab file and follows it.
It is recommended that instead of a device name, a UUID is used. A UUID is a universally unique identifier for the device. This hexadecimal value doesn’t change even as you remove hard drives or replace them, or move their connections around. In other words the hard drives don’t get lost in the shuffle. If you have more than one hard drive in the box like me that would be a tremendous help keeping tabs.
The fstab lists the root partition and swap partition. Ubuntu plans to use a swap file by Ubuntu 17.04 but fstab rules still applies. Each partition contains the name or UUID, mount point, filesystem type, mount options, etc. Don’t worry about the details, fstab is automatically generated for you upon installation. You do get extra points for modifying it for security, and if you have more esoteric plans for your partitions.
I use 4 hard drives and an SSD. For this discussion’s purpose the SSD is like the hard drives and it’s also where I boot and keep my root partition. I have the 4 hard drives formed into a RAID array. I then virtually created logical volumes to utilize the entire storage available. In my case, that’s 1 SSD plus the RAID array.
I understand that putting noexec, nosuid on fstab options for a partition makes it more secure but not all partitions should have them. I put them in my LV’s which contain music and video. I also got advised to put them in the shared memory partition – /dev/shm.
The jury is still out if I should put it in my /home partition.
Before modifying the /etc/fstab file, I created a backup file and saved it as /etc/fstab.backup. If I missed something and the system won’t boot, I can just go back to the working fstab file as before.
After modifying fstab, reboot to check if the changes made are fine.