When you enter the uuidgen command, you will get any of more than 3.40 × 10 38 possible responses.
These identifiers are for all practical purposes unique. Check if it's on your system by typing "which uuidgen". You can get a feel for how Linux generates UUIDs by running uuidgen yourself. The 76E8-CACF device mounted as /dev/sdc1 is a USB drive that is temporarily in use. You can also check out the by-uuid file to view the relationships: One way to view how the UUIDs connect with the device names (e.g., /dev/sda1) is to use the blkid command. Those lengthy device identifiers that you see in /etc/fstab that are labeled UUID (universally unique identifier) are 128 bit (32 hex characters) long and arranged in an 8-4-4-4-12 character sequence.
The /etc/fstab file shown above is unusual in that a new OS was just recently installed on /dev/sda and the /home folder from the system before the upgrade (on a separate disk) was then remounted after the first reference to /home was commented out. The btrfs file system is a modern copy-on-write (CoW) filesystem for Linux that provides advanced features while also focusing on fault tolerance, repair and easy administration. determines if file-system checking should be done at boot time (0 = not).determines if the file system might be dumped (0 = not) using the dump command (not often used).shows the file system type (could be ext4, xfs, btrfs, f2fs, vfat, ntfs, hfsplus, tmpfs, sysfs, proc, iso9660, udf, squashfs, nfs, cifs or something else).describes the disk partition (more on the UUIDs below).UUID=d867ced1-8d81-47c6-b299-3365ba8a02de /home ext4 defaultsĮach line in the file (other than the comments) represents a file system and has six fields.
# After editing this file, run 'systemctl daemon-reload' to update systemd # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info. # Accessible filesystems, by reference, are maintained under '/dev/disk/'. # Created by anaconda on Fri Mar 12 12:26:55 2021 Here's an example of an /etc/fstab file on a Fedora system: $ cat /etc/fstab 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. It contains information that allows the system to connect to disk partitions and determine where they should be mounted in the file system. The /etc/fstab file is a very important file on Linux systems.