man > xfs_copy(8)

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 ... ]
       xfs_copy -V

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  supports
       sparse files efficiently.

       xfs_copy should only be used to copy unmounted filesystems, read-only mounted filesystems, or
       frozen  filesystems (see xfs_freeze(8)).  Otherwise, the generated filesystem(s) would be in‐
       consistent 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(8)/xfsrestore(8) should be used to  gener‐
       ate  the  new  filesystem(s)  instead  of dd(1) or other programs that do block-by-block disk
       copying.

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

       xfs_copy uses pthreads(7) to perform simultaneous parallel writes.  xfs_copy creates one  ad‐
       ditional  thread  for  each  target to be written.  All threads die if xfs_copy terminates or
       aborts.

OPTIONS
       -d     Create a duplicate (true clone) filesystem. 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).

       -b     The buffered option can be used to ensure direct IO is not attempted  to  any  of  the
              target files. This is useful when the filesystem holding the target file does not sup‐
              port direct IO.

       -L log Specifies    the    location    of    the    log    if   the   default   location   of
              /var/tmp/xfs_copy.log.XXXXXX is not desired.

       -V     Prints the version number and exits.

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 op‐
       tion. 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 terminates, 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 immedi‐
       ately 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.xfs(8)  and
       xfsdump(8)/xfsrestore(8) be used instead of using xfs_copy and xfs_growfs(8).  The filesystem
       layout resulting from using xfs_copy/xfs_growfs is almost always worse than the result of us‐
       ing  mkfs.xfs/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(8)  works,  and  not
       due to any shortcoming in xfs_copy itself.

CAVEATS
       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.

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

                                                                                         xfs_copy(8)