Btrfs Filesystem /etc/fstab Entry To Mount It Automatically At Linux System Startup

To mount a Btrfs filesystem automatically at Linux system startup, you can add an entry to the /etc/fstab file. The /etc/fstab file is a configuration file that contains a list of filesystems and the options used to mount them.

Here is an example of an /etc/fstab entry for a Btrfs filesystem:

/dev/sda1     /mnt/btrfs   btrfs   defaults    0   0

This entry specifies that the Btrfs filesystem located on the device /dev/sda1 should be mounted at the mount point /mnt/btrfs with the default options. The defaults option specifies a set of default mount options, which include rw, suid, dev, exec, auto, nouser, and async.

You can customize the mount options by specifying a different option string in place of defaults. For example, to mount the Btrfs filesystem in read-only mode, you can use the ro option:

/dev/sda1     /mnt/btrfs   btrfs   ro    0   0

You can also specify the subvol= option to specify a specific subvolume to mount. For example:

/dev/sda1     /mnt/btrfs   btrfs   subvol=subvolume1    0   0

This will mount the subvolume subvolume1 of the Btrfs filesystem on /dev/sda1 at the mount point