filesystem

sudo apt-get install btrfs-tools
# mkfs.btrfs /dev/sdb
sudo mkfs.btrfs -L lxc /dev/sdb1

# list volumes
btrfs filesystem show

# list subvolumes
mount /dev/sdb1 /mnt/
btrfs subvolume list /mnt/

# create subvolume
sudo btrfs subvolume create /mnt/@sub1

# get default subvolume
btrfs subvolume get-default /mnt/

# set default subvolume
btrfs subvolume set-default 299 /mnt/

# mount subvolume
mount -o subvol=new_subvol /dev/sdb1 /tmp/2

btrfs filesystem resize 64g /mnt

# enable comprsssion (mountparameter)
compress

# /etc/fstab