NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPTIMIZATIONS | REPAIRS | EXIT CODE | CAVEATS | SEE ALSO | COLOPHON

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

NAME         top

       xfs_scrub - check the contents of a mounted XFS filesystem

SYNOPSIS         top

       xfs_scrub [ -abCemnTvx ] mount-point
       xfs_scrub -V

DESCRIPTION         top

       xfs_scrub attempts to check and repair all metadata in a mounted XFS
       filesystem.

       WARNING!  This program is EXPERIMENTAL, which means that its behavior
       and interface could change at any time!

       xfs_scrub asks the kernel to scrub all metadata objects in the
       filesystem.  Metadata records are scanned for obviously bad values
       and then cross-referenced against other metadata.  The goal is to
       establish a reasonable confidence about the consistency of the
       overall filesystem by examining the consistency of individual
       metadata records against the other metadata in the filesystem.
       Damaged metadata can be rebuilt from other metadata if there exists
       redundant data structures which are intact.

       Filesystem corruption and optimization opportunities will be logged
       to the standard error stream.  Enabling verbose mode will increase
       the amount of status information sent to the output.

       If the kernel scrub reports that metadata needs repairs or
       optimizations and the user does not pass -n on the command line, this
       program will ask the kernel to make the repairs and to perform the
       optimizations.  See the sections about optimizations and repairs for
       a list of optimizations and repairs known to this program.  The
       kernel may not support repairing or optimizing the filesystem.  If
       this is the case, the filesystem must be unmounted and xfs_repair(8)
       run on the filesystem to fix the problems.

OPTIONS         top

       -a errors
              Abort if more than this many errors are found on the
              filesystem.

       -b     Run in background mode.  If the option is specified once, only
              run a single scrubbing thread at a time.  If given more than
              once, an artificial delay of 100us is added to each scrub call
              to reduce CPU overhead even further.

       -C fd  This option causes xfs_scrub to write progress information to
              the specified file description so that the progress of the
              filesystem check can be monitored.  If the file description is
              a tty, a fancy progress bar is rendered.  Otherwise, a simple
              numeric status dump compatible with the fsck -C format is
              output.

       -e     Specifies what happens when errors are detected.  If shutdown
              is given, the filesystem will be taken offline if errors are
              found.  If continue is given, no action is taken if errors are
              found; this is the default behavior.

       -k     Do not call TRIM on the free space.

       -m file
              Search this file for mounted filesystems instead of /etc/mtab.

       -n     Only check filesystem metadata.  Do not repair or optimize
              anything.

       -T     Print timing and memory usage information for each phase.

       -v     Enable verbose mode, which prints periodic status updates.

       -V     Prints the version number and exits.

       -x     Read all file data extents to look for disk errors.  xfs_scrub
              will issue O_DIRECT reads to the block device directly.  If
              the block device is a SCSI disk, it will instead issue READ
              VERIFY commands directly to the disk.  These actions will
              confirm that all file data blocks can be read from storage.

OPTIMIZATIONS         top

       Optimizations supported by this program include, but are not limited
       to:

       · Instructing the underlying storage to discard unused extents via
         the TRIM ioctl.

REPAIRS         top

       This program currently does not support making any repairs.
       Corruptions can only be fixed by unmounting the filesystem and
       running xfs_repair(8).

EXIT CODE         top

       The exit code returned by xfs_scrub is the sum of the following
       conditions:
            0    - No errors
            1    - File system errors left uncorrected
            2    - File system optimizations possible
            4    - Operational error
            8    - Usage or syntax error

CAVEATS         top

       xfs_scrub is an immature utility!  Do not run this program unless you
       have backups of your data!  This program takes advantage of in-kernel
       scrubbing to verify a given data structure with locks held and can
       keep the filesystem busy for a long time.  The kernel must be new
       enough to support the SCRUB_METADATA ioctl.

       If errors are found and cannot be repaired, the filesystem must be
       unmounted and repaired.

SEE ALSO         top

       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, see
       ⟨http://oss.sgi.com/bugzilla/buglist.cgi?product=XFS⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨git://oss.sgi.com/xfs/cmds/xfsprogs⟩ on 2018-04-30.  (At that time,
       the date of the most recent commit that was found in the repository
       was 2018-04-26.)  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

                                                                xfs_scrub(8)

Pages that refer to this page: ioctl_xfs_scrub_metadata(2)xfs_scrub_all(8)