btrfs-check(8) check or repair an unmounted btrfs filesystem


btrfs check [options] <device>


btrfs check is used to check or repair an unmounted btrfs filesystem.


Since btrfs is under development, the btrfs check capabilities are continuously enhanced. It's highly recommended to read the following btrfs wiki before executing btrfs check with --repair option: m[blue][]

btrfsck is an alias of btrfs check command and is now deprecated.


-s|--super <superblock>

use <superblock>th superblock copy, valid values are 0 up to 2 if the respective superblock offset is within the filesystem


use the first backup roots stored in the superblock that is valid


try to repair the filesystem


run in read-only mode (default)


create a new CRC tree and recalculate all checksums


create a new extent tree


verify checksums of data blocks


indicate progress at various checking phases


verify qgroup accounting and compare against filesystem accounting

-E|--subvol-extents <subvolid>

show extent state for the given subvolume

-r|--tree-root <bytenr>

use the given bytenr for the tree root

--chunk-root <bytenr>

use the given bytenr for the chunk tree root


btrfs check returns a zero exit status if it succeeds. Non zero is returned in case of failure.


btrfs is part of btrfs-progs. Please refer to the btrfs wiki m[blue][] for further details.