phpman > man > xfs_scrub(8)

Markdown | JSON | MCP    

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



NAME
       xfs_scrub - check and repair the contents of a mounted XFS filesystem

SYNOPSIS
       xfs_scrub [ -abCemnTvx ] mount-point
       xfs_scrub -V

DESCRIPTION
       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 op‐
       timizing  the  filesystem.  If this is the case, the filesystem must be unmounted and xfs_re‐‐
       pair(8) run on the filesystem to fix the problems.

OPTIONS
       -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  de‐
              scription  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  in‐
              stead issue READ VERIFY commands directly to the disk.  If media errors are found, the
              error report will include the disk offset, in bytes.  If the  media  errors  affect  a
              file,  the report will also include the inode number and file offset, in bytes.  These
              actions will confirm that all file data blocks can be read from storage.

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

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

       • Updating secondary superblocks to match the primary superblock.

       • Turning off shared block write checks for files that no longer share blocks.

REPAIRS
       Repairs are performed by calling into the kernel.  This limits the scope of repair activities
       to rebuilding primary data structures from secondary data structures, or secondary structures
       from primary structures.  The existence of secondary data  structures  may  require  features
       that  can  only  be turned on from mkfs.xfs(8).  If errors cannot be repaired, the filesystem
       must be unmounted and xfs_repair(8) run.  Repairs supported by the kernel  include,  but  are
       not limited to:

       • Reconstructing extent allocation data.

       • Rebuilding free space information.

       • Rebuilding inode indexes.

       • Fixing minor corruptions of inode records.

       • Recalculating reference count information.

       • Reconstructing reverse mapping data from primary extent allocation data.

       • Scheduling a quotacheck for the next mount.

       If  corrupt  metadata  is successfully repaired, this program will log that a repair has suc‐
       ceeded instead of a corruption report.

EXIT CODE
       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
       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
       xfs_repair(8).



                                                                                        xfs_scrub(8)
xfs_scrub(8)
NAME SYNOPSIS DESCRIPTION OPTIONS
-a errors -b Run in background mode. If the option is specified once, only run a single scrubbing -C fd This option causes xfs_scrub to write progress information to the specified file de‐ -e Specifies what happens when errors are detected. If shutdown is given, the filesystem -k Do not call TRIM on the free space. -m file -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
OPTIMIZATIONS REPAIRS EXIT CODE CAVEATS SEE ALSO

Generated by phpman local Author: Che Dong Under GNU General Public License
2026-06-15 04:37 @216.73.216.200
CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
Valid XHTML 1.0 TransitionalValid CSS!

^_back to top