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🗄️ Mounting BTRFS subvolumes
Monday 27 February 2023 2 versions

If you have installed GNU/Linux with BTRFS as the filesystem, chances are that your OS installer has used sub-volumes for the `root`, `home` and other mount points. 🗄️

You can verify this by mounting the actual root filesystem device and listing its contents:

    1# ls -l /mnt/
    2total 0
    3drwxr-xr-x 1 root root  204 Feb 22 13:28 @
    4drwxr-xr-x 1 root root  180 Feb 22 14:29 @cache
    5drwxr-xr-x 1 root root   10 Dec  2 10:52 @home
    6drwxr-xr-x 1 root root  482 Feb 26 00:00 @log
    7drwxr-x--- 1 root root  350 Feb 23 15:40 @root
    8drwxr-xr-x 1 root root   14 Oct 19 07:42 @srv
    9drwxrwxrwt 1 root root 1576 Feb 27 17:18 @tmp

Here `@`, `@home`, `@log` etc. are the BTRFS sub-volumes. `@` is the OS root sub-volume. You can mount by giving the `-osubvol=@` option to the mount command:

     1# mount -osubvol=@ /dev/dm-0 /mnt/
     2# ls -l /mnt/
     3total 24
     4lrwxrwxrwx 1 root root    7 Feb  1 02:21 bin -> usr/bin
     5drwxr-xr-x 1 root root  208 Feb 22 13:30 boot
     6drwxr-xr-x 1 root root    8 Oct 20 18:39 dev
     7drwxr-xr-x 1 root root 5018 Feb 25 10:56 etc
     8drwxr-xr-x 1 root root    0 Dec  2 10:48 home
     9lrwxrwxrwx 1 root root    7 Feb  1 02:21 lib -> usr/lib
    10lrwxrwxrwx 1 root root    7 Feb  1 02:21 lib64 -> usr/lib
    11drwxr-xr-x 1 root root   22 Dec 16 13:00 mnt
    12drwxr-xr-x 1 root root  214 Feb 23 15:50 opt
    13drwxr-xr-x 1 root root    0 Dec  2 10:48 proc
    14drwxr-xr-x 1 root root   66 Oct 20 18:47 root
    15    ....    ....    ....

#linux #btrfs #systemrescue #filesystem

# Backlinks

- 🔁 Migrate from UEFI to (Legacy) BIOS Tuesday 28 February 2023

# See Also

- 🎧 Chromebox-Audio Monday 27 February 2023