xfs_copy(8) — Linux manual page


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

NAME         top

       xfs_copy - copy the contents of an XFS filesystem

SYNOPSIS         top

       xfs_copy [ -bd ] [ -L log ] source target1 [ target2 ... ]
       xfs_copy -V

DESCRIPTION         top

       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
       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(8)/xfsrestore(8) should be used to generate
       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

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

OPTIONS         top

       -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 support
              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         top

       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 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 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         top

       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
       using 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         top

       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         top

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

COLOPHON         top

       This page is part of the xfsprogs (utilities for XFS filesystems)
       project.  Information about the project can be found at 
       ⟨http://xfs.org/⟩.  If you have a bug report for this manual page,
       send it to linux-xfs@vger.kernel.org.  This page was obtained
       from the project's upstream Git repository
       ⟨https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git⟩ on
       2021-08-27.  (At that time, the date of the most recent commit
       that was found in the repository was 2021-08-20.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org


Pages that refer to this page: xfs_db(8)xfsdump(8)xfs_logprint(8)xfs_metadump(8)