Ubuntu Manpage: xfs_check - check XFS filesystem consistency

Provided by: xfsprogs_3.1.9ubuntu2.1_amd64

NAME

       xfs_check - check XFS filesystem consistency

SYNOPSIS

       xfs_check [ -i ino ] ... [ -b bno ] ... [ -f ] [ -s ] [ -v ] [ -l logdev ] device

DESCRIPTION

       xfs_check  checks  whether an XFS filesystem is consistent.  It is normally run only when there is reason
       to believe that the filesystem has a consistency problem.  The filesystem to be checked is  specified  by
       the device argument, which should be the disk or volume device for the filesystem.  Filesystems stored in
       files  can  also  be checked, using the -f flag. The filesystem should normally be unmounted or read-only
       during the execution of xfs_check.  Otherwise, spurious problems are reported.

       Note that using xfs_check is NOT recommended. Please use xfs_repair -n instead,  for  better  scalability
       and speed.

OPTIONS

-f Specifies that the filesystem image to be processed is stored in a regular file at device (see the
mkfs.xfs(8) -d file option). This might happen if an image copy of a filesystem has been made into
an ordinary file.

-l logdev
Specifies the device where the filesystem's external log resides. Only for those filesystems
which use an external log. See the mkfs.xfs(8) -l option, and refer to xfs(5) for a detailed
description of the XFS log.

-s Specifies that only serious errors should be reported. Serious errors are those that make it
impossible to find major data structures in the filesystem. This option can be used to cut down
the amount of output when there is a serious problem, when the output might make it difficult to
see what the real problem is.

-v Specifies verbose output; it is impossibly long for a reasonably-sized filesystem. This option is
intended for internal use only.

-i ino Specifies verbose behavior for the specified inode ino. For instance, it can be used to locate
all the blocks associated with a given inode.

-b bno Specifies verbose behavior for the specific filesystem block at bno. For instance, it can be used
to determine what a specific block is used for. The block number is a "file system block number".
Conversion between disk addresses (i.e. addresses reported by xfs_bmap(8)) and file system blocks
may be accomplished using xfs_db(8)'s convert command.

Any output that is produced when xfs_check is not run in verbose mode indicates that the filesystem has
an inconsistency. The filesystem can be repaired using either xfs_repair(8) to fix the filesystem in
place, or by using xfsdump(8) and mkfs.xfs(8) to dump the filesystem, make a new filesystem, then use
xfsrestore(8) to restore the data onto the new filesystem. Note that xfsdump may fail on a corrupt
filesystem. However, if the filesystem is mountable, xfsdump can be used to try and save important data
before repairing the filesystem with xfs_repair. If the filesystem is not mountable though, xfs_repair
is the only viable option.

DIAGNOSTICS

If the filesystem is completely corrupt, a core dump might be produced instead of the message
device is not a valid filesystem

If the filesystem is very large (has many files) then xfs_check might run out of memory. In this case the
message
out of memory
is printed.

The following is a description of the most likely problems and the associated messages. Most of the
diagnostics produced are only meaningful with an understanding of the structure of the filesystem.

agf_freeblks n, counted m in ag a
The freeblocks count in the allocation group header for allocation group a doesn't match the
number of blocks counted free.

agf_longest n, counted m in ag a
The longest free extent in the allocation group header for allocation group a doesn't match the
longest free extent found in the allocation group.

agi_count n, counted m in ag a
The allocated inode count in the allocation group header for allocation group a doesn't match the
number of inodes counted in the allocation group.

agi_freecount n, counted m in ag a
The free inode count in the allocation group header for allocation group a doesn't match the
number of inodes counted free in the allocation group.

block a/b expected inum 0 got i
The block number is specified as a pair (allocation group number, block in the allocation group).
The block is used multiple times (shared), between multiple inodes. This message usually follows
a message of the next type.

block a/b expected type unknown got y
The block is used multiple times (shared).

block a/b type unknown not expected
The block is unaccounted for (not in the freelist and not in use).

link count mismatch for inode nnn (name xxx), nlink m, counted n
The inode has a bad link count (number of references in directories).

rtblock b expected inum 0 got i
The block is used multiple times (shared), between multiple inodes. This message usually follows
a message of the next type.

rtblock b expected type unknown got y
The real-time block is used multiple times (shared).

rtblock b type unknown not expected
The real-time block is unaccounted for (not in the freelist and not in use).

sb_fdblocks n, counted m
The number of free data blocks recorded in the superblock doesn't match the number counted free in
the filesystem.

sb_frextents n, counted m
The number of free real-time extents recorded in the superblock doesn't match the number counted
free in the filesystem.

sb_icount n, counted m
The number of allocated inodes recorded in the superblock doesn't match the number allocated in
the filesystem.

sb_ifree n, counted m
The number of free inodes recorded in the superblock doesn't match the number free in the
filesystem.

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

DIAGNOSTICS

SEE ALSO