btrfs-1

[samus@localhost ~]$ sudo btrfs fi show /mnt2
Label: none  uuid: e1ab0dfd-6fa9-492b-a3a3-1a28b9acb50b
        Total devices 1 FS bytes used 21.10GiB
        devid    1 size 21.85GiB used 21.85GiB path /dev/sda3

[samus@localhost ~]$ sudo btrfs balance start -dusage=0 /mnt2
Done, had to relocate 0 out of 33 chunks
[samus@localhost ~]$ sudo btrfs balance start -dusage=15 -dlimit=10 -musage=25 -mlimit=10 /mnt2
Done, had to relocate 0 out of 33 chunks