====== btrfs ======
===== Filesystem =====

  btrfs filesystem df
  btrfs filesystem show
  btrfs filesystem defragment /path
  btrfs filesystem label /path <label>

===== Subvolumes/Snapshots =====

  btrfs subvolume create <name>
  btrfs subvolume show /path/to/subvolume
  btrfs subvolume list /path
  btrfs subvolume snapshot /old /new
  btrfs sub snap -r /old /.snapshot/ro     # read only

===== Mounten / Default =====
  btrfs subv set-default 258 /path
  mount -o subvol=/subv/0/vol0 /dev/sdb1 /path


===== Dokus und Links =====
  * https://en.opensuse.org/SDB:BTRFS
  * https://btrfs.wiki.kernel.org/index.php/Status