btrfs-progs/Documentation/btrfs-check.asciidoc

btrfs-check(8)
==============

NAME
----
btrfs-check - check or repair an unmounted btrfs filesystem

SYNOPSIS
--------
*btrfs check* [options] <device>

DESCRIPTION
-----------
*btrfs check* is used to check or repair an unmounted btrfs filesystem.

NOTE: 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: +
https://btrfs.wiki.kernel.org/index.php/Btrfsck

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

OPTIONS
-------
-s|--super <superblock>::
use <superblock>th superblock copy, valid values are 0 up to 2 if the
respective superblock offset is within the filesystem
-b|--backup::
use the first backup roots stored in the superblock that is valid
--repair::
try to repair the filesystem
--readonly::
run in read-only mode (default)
--init-csum-tree::
create a new CRC tree and recalculate all checksums
--init-extent-tree::
create a new extent tree
--check-data-csum::
verify checksums of data blocks
-p|--progress::
indicate progress at various checking phases
--qgroup-report::
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

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

AVAILABILITY
------------
*btrfs* is part of btrfs-progs.
Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for
further details.

SEE ALSO
--------
`mkfs.btrfs`(8),
`btrfs-scrub`(8),
`btrfs-rescue`(8)