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



NAME
       xfs_copy - copy the contents of an XFS filesystem

SYNOPSIS
       xfs_copy [ -bd ] [ -L log ] source target1 [ target2 target3 ... ]

DESCRIPTION
       xfs_copy  copies  an  XFS filesystem to one or more targets in parallel
       (see xfs(5)).  The first (source) argument must be the pathname of  the
       device  or file containing the XFS filesystem.  The remaining arguments
       specify one or more target devices or file  names.   If  the  pathnames
       specify devices, a copy of the source XFS filesystem is created on each
       device.  The target can also be the name of a regular  file,  in  which
       case an image of the source XFS filesystem is created in that file.  If
       the file does not exist, xfs_copy creates the file.  The length of  the
       resulting file is equal to the size of the source filesystem.  However,
       if the file is created on an XFS filesystem, the file consumes  roughly
       the  amount  of  space  actually  used  in the source filesystem by the
       filesystem and the XFS log.  The space saving is because xfs_copy seeks
       over  free  blocks  instead of copying them and the XFS filesystem sup-
       ports sparse files efficiently.

       xfs_copy should only be used to copy unmounted  filesystems,  read-only
       mounted filesystems, or frozen filesystems (see xfs_freeze(8)).  Other-
       wise, the generated filesystem(s) would be inconsistent or corrupt.

       xfs_copy does not alter the source filesystem in  any  way.   Each  new
       (target) filesystem is identical to the original filesystem except that
       new filesystems each have a new unique  filesystem  identifier  (UUID).
       Therefore, if both the old and new filesystems will be used as separate
       distinct filesystems, xfs_copy or xfsdump/xfsrestore should be used  to
       generate  the new filesystem(s) instead of dd(1) or other programs that
       do block-by-block disk copying.

       The -d (duplicate) option can be used if a true clone is desired.  This
       should be done only if the new filesystem will be used as a replacement
       for the original filesystem (such as in the case of disk replacement).

       xfs_copy uses synchronous  writes  to  ensure  that  write  errors  are
       detected.

       The  -b  (buffered)  option  can  be  used  to  ensure direct IO is not
       attempted to any of the target files.  This is useful when the filesys-
       tem  holding the target file does not support direct IO.  xfs_copy also
       uses pthreadss to perform simultaneous parallel writes.  xfs_copy  cre-
       ates  one additional thread for each target to be written.  All threads
       die if xfs_copy terminates or aborts.

       xfs_copy does not copy XFS filesystems that have a real-time section or
       XFS  filesystems  with  external  logs.  In both cases, xfs_copy aborts
       with an error message.

DIAGNOSTICS
       xfs_copy reports errors to both stderr and in more detailed form  to  a
       generated     log     file     whose    name    is    of    the    form
       /var/tmp/xfs_copy.log.XXXXXX or a log file specified by the -L  option.
       If  xfs_copy  detects  a  write error on a target, the copy of that one
       target is aborted and an error message is issued to both stderr and the
       log  file,  but  the rest of the copies continue.  When xfs_copy termi-
       nates, all aborted targets are reported to  both  stderr  and  the  log
       file.

       If  all  targets  abort  or  if  there  is  an error reading the source
       filesystem, xfs_copy immediately aborts.

       xfs_copy returns an exit code of 0  if  all  targets  are  successfully
       copied and an exit code of 1 if any target fails.

NOTES
       When  moving  filesystems  from  one  disk  to another, if the original
       filesystem is significantly smaller than the new filesystem,  and  will
       be  made  larger, we recommend that mkfs and xfsdump/xfsrestore be used
       instead of  using  xfs_copy  and  xfs_growfs.   The  filesystem  layout
       resulting  from  using  xfs_copy/xfs_growfs is almost always worse than
       the result of using mkfs/xfsdump/xfsrestore but in the  case  of  small
       filesystems, the differences can have a significant performance impact.
       This is due to the way xfs_growfs works, and not due to any shortcoming
       in xfs_copy itself.

SEE ALSO
       mkfs.xfs(8),  xfsdump(8),  xfsrestore(8), xfs_freeze(8), xfs_growfs(8),
       xfs(5).



                                                                   xfs_copy(8)