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xfs_metadump(8)                                System Manager's Manual                                xfs_metadump(8)



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 argu‐
       ment must be the pathname of the device or file containing the XFS filesystem and the target  argument  speci‐
       fies  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 par‐
       tially 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 std‐
              out.

       -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.

       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 [email protected].



                                                                                                      xfs_metadump(8)