The /etc/fstab file is a very important file on Linux systems. It contains information that allows the system to connect to disk partitions and determine where they should be mounted in the file system. While this file has played an important role over the years, its format has changed with the introduction of UUIDs and, on some systems, a more reliable file-system type.
Here’s an example of an /etc/fstab file on a Fedora system:
$ cat /etc/fstab
# Created by anaconda on Fri Mar 12 12:26:55 2021
# Accessible filesystems, by reference, are maintained under ‘/dev/disk/’.
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info.
# After editing this file, run ‘systemctl daemon-reload’ to update systemd
# units generated from this file.
UUID=a9e33237-9114-44ae-afd5-8ddb231d301f / btrfs subvol=root 0 0
UUID=15f42905-5897-4804-9c51-e6d5e169e6c2 /boot ext4 defaults 1 2
#UUID=a9e33237-9114-44ae-afd5-8ddb231d301f /home btrfs subvol=home 0 0
UUID=d867ced1-8d81-47c6-b299-3365ba8a02de /home ext4 defaults
Each line in the file (other than the comments) represents a file system and has six fields.
Source:: Network World – Linux