xfs_admin(8) — Linux manual page


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

NAME         top

       xfs_admin - change parameters of an XFS filesystem

SYNOPSIS         top

       xfs_admin [ -eflpu ] [ -c 0|1 ] [ -L label ] [ -U uuid ] device [
       logdev ]
       xfs_admin -V

DESCRIPTION         top

       xfs_admin uses the xfs_db(8) command to modify various parameters of
       a filesystem.

       Devices that are mounted cannot be modified.  Administrators must
       unmount filesystems before xfs_admin or xfs_db(8) can convert
       parameters.  A number of parameters of a mounted filesystem can be
       examined and modified using the xfs_growfs(8) command.

       The optional logdev parameter specifies the device special file where
       the filesystem's external log resides.  This is required only for
       filesystems that use an external log.  See the mkfs.xfs -l option,
       and refer to xfs(5) for a detailed description of the XFS log.

OPTIONS         top

       -e     Enables unwritten extent support on a filesystem that does not
              already have this enabled (for legacy filesystems, it can't be
              disabled anymore at mkfs time).

       -f     Specifies that the filesystem image to be processed is stored
              in a regular file at device (see the mkfs.xfs -d file option).

       -j     Enables version 2 log format (journal format supporting larger
              log buffers).

       -l     Print the current filesystem label.

       -p     Enable 32bit project identifier support (PROJID32BIT feature).

       -u     Print the current filesystem UUID (Universally Unique

       -c 0|1 Enable (1) or disable (0) lazy-counters in the filesystem.

              Lazy-counters may not be disabled on Version 5 superblock
              filesystems (i.e. those with metadata CRCs enabled).

              This operation may take quite a bit of time on large
              filesystems as the entire filesystem needs to be scanned when
              this option is changed.

              With lazy-counters enabled, the superblock is not modified or
              logged on every change of the free-space and inode counters.
              Instead, enough information is kept in other parts of the
              filesystem to be able to maintain the counter values without
              needing to keep them in the superblock. This gives significant
              improvements in performance on some configurations and
              metadata intensive workloads.

       -L label
              Set the filesystem label to label.  XFS filesystem labels can
              be at most 12 characters long; if label is longer than 12
              characters, xfs_admin will truncate it and print a warning
              message.  The filesystem label can be cleared using the
              special "--" value for label.

       -U uuid
              Set the UUID of the filesystem to uuid.  A sample UUID looks
              like this: "c1b9d5a2-f162-11cf-9ece-0020afc76f16".  The uuid
              may also be nil, which will set the filesystem UUID to the
              null UUID.  The uuid may also be generate, which will generate
              a new UUID for the filesystem.  Note that on CRC-enabled
              filesystems, this will set an incompatible flag such that
              older kernels will not be able to mount the filesystem.  To
              remove this incompatible flag, use restore, which will restore
              the original UUID and remove the incompatible feature flag as

       -V     Prints the version number and exits.

       The mount(8) manual entry describes how to mount a filesystem using
       its label or UUID, rather than its block special device name.

SEE ALSO         top

       mkfs.xfs(8), mount(8), xfs_db(8), xfs_growfs(8), xfs_repair(8),

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
       2020-09-18.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-09-04.)  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


Pages that refer to this page: fstab(5)xfs(5)mkfs.xfs(8)mount(8)xfs_db(8)xfs_repair(8)