NAME

       xfs_metadump - copy XFS filesystem metadata to a file

SYNOPSIS

       xfs_metadump [ -aefFgow ] [ -m max_extents ] ] [ -l logdev ] source target
       xfs_metadump -V

DESCRIPTION

       xfs_metadump  is  a  debugging  tool  that copies the metadata from an XFS filesystem to a
       file.  The source argument must be the pathname of the device or file containing  the  XFS
       filesystem  and  the target argument specifies the destination file name.  If target is -,
       then the output is sent to stdout. This allows the output  to  be  redirected  to  another
       program such as a compression application.

       xfs_metadump  may  only  be  used  to  copy  unmounted  filesystems,  or read-only mounted
       filesystems.

       xfs_metadump does not alter the source filesystem in  any  way.  The  target  image  is  a
       contiguous (non-sparse) file containing all the filesystem's metadata and indexes to where
       the blocks were copied from.

       By default, xfs_metadump obfuscates most file (regular file, directory and symbolic  link)
       names  and  extended  attribute  names  to  allow  the  dumps to be sent without revealing
       confidential information. Extended attribute values are zeroed and no data is copied.  The
       only  exceptions are file or attribute names that are 4 or less characters in length. Also
       file names that span extents (this can only occur with the mkfs.xfs(8)  options  where  -n
       size > -b size) are not obfuscated. Names between 5 and 8 characters in length inclusively
       are partially obfuscated.

       xfs_metadump should not be used for any purposes other than for  debugging  and  reporting
       filesystem  problems.  The  most common usage scenario for this tool is when xfs_repair(8)
       fails to repair a filesystem and a metadump image can be sent for analysis.

       The file generated by xfs_metadump can be restored to filesystem image  (minus  the  data)
       using the xfs_mdrestore(8) tool.

OPTIONS

       -a     Copies  entire  metadata  blocks.  Normally, xfs_metadump will zero any stale bytes
              interspersed with in-use metadata.  Use this option to copy full  metadata  blocks,
              to  provide  more  debugging information for a corrupted filesystem.  Note that the
              extra data will be unobfuscated.

       -e     Stops the dump on a read error. Normally, it will ignore read errors and  copy  all
              the metadata that is accessible.

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

       -F     Specifies that we want to continue even if the superblock magic is not correct.  If
              the source is truly not an XFS filesystem, the resulting image will be useless, and
              xfs_metadump may crash.

       -g     Shows dump progress. This is sent to stdout if the target is a file or to stderr if
              the target is stdout.

       -l logdev
              For filesystems which use an external log, this  specifies  the  device  where  the
              external  log  resides.  The  external  log  is  not copied, only internal logs are
              copied.

       -m     Set the maximum size of an  allowed  metadata  extent.   Extremely  large  metadata
              extents  are  likely  to be corrupt, and will be skipped if they exceed this value.
              The default size is 1000 blocks.

       -o     Disables obfuscation of file names and extended attributes.

       -w     Prints warnings of inconsistent metadata encountered to  stderr.  Bad  metadata  is
              still copied.

       -V     Prints the version number and exits.

DIAGNOSTICS

       xfs_metadump  returns an exit code of 0 if all readable metadata is successfully copied or
       1 if a write error occurs or a read error occurs and the -e option used.

NOTES

       As xfs_metadump copies metadata only, it does not matter if the source  filesystem  has  a
       realtime section or not. If the filesystem has an external log, it is not copied. Internal
       logs are copied and any outstanding log transactions are not obfuscated  if  they  contain
       names.

       xfs_metadump is a shell wrapper around the xfs_db(8) metadump command.

SEE ALSO

       xfs_repair(8), xfs_mdrestore(8), xfs_freeze(8), xfs_db(8), xfs_copy(8), xfs(5)

BUGS

       Email bug reports to linux-xfs@vger.kernel.org.

                                                                                  xfs_metadump(8)