btrfs subvolume list -s </srv>btrfs subvolume delete </srv/lxc/website/snaps/snap1/rootfs>Adapted from: Linux.com
btrfs filesystem df </srv>btrfs balance start -musage=<0> </srv>btrfs balance start -dusage=<0> </srv>
Up the -
usage in increments starting from 0 to 50 in increments of 5