скопировать содержимое файловой системы XFS (copy the contents of an XFS filesystem)
Имя (Name)
xfs_copy - copy the contents of an XFS filesystem
Синопсис (Synopsis)
xfs_copy [ -bd ] [ -L log ] source target1 [ target2 ... ]
xfs_copy -V
Описание (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
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
detected.
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.
Параметры (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 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.
Диагностика (Diagnostic)
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.
Примечание (Note)
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.
Предостережение (Caveat)
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.
Смотри также (See also)
mkfs.xfs(8), xfsdump(8), xfsrestore(8), xfs_freeze(8),
xfs_growfs(8), xfs(5).
