NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | COLOPHON

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

NAME         top

       xfs_bmap - print block mapping for an XFS file

SYNOPSIS         top

       xfs_bmap [ -adlpv ] [ -n num_extents ] file
       xfs_bmap -V

DESCRIPTION         top

       xfs_bmap prints the map of disk blocks used by files in an XFS
       filesystem.  The map lists each extent used by the file, as well as
       regions in the file that do not have any corresponding blocks
       (holes).  Each line of the listings takes the following form:

              extent: [startoffset..endoffset]: startblock..endblock

       Holes are marked by replacing the startblock..endblock with hole.
       All the file offsets and disk blocks are in units of 512-byte blocks,
       no matter what the filesystem's block size is.

OPTIONS         top

       -a     If this option is specified, information about the file's
              attribute fork is printed instead of the default data fork.

       -c     If this option is specified, information about the file's copy
              on write fork is printed instead of the default data fork.

       -d     If portions of the file have been migrated offline by a DMAPI
              application, a DMAPI read event will be generated to bring
              those portions back online before the disk block map is
              printed.  However if the -d option is used, no DMAPI read
              event will be generated for a DMAPI file and offline portions
              will be reported as holes.

       -e     If this option is used, xfs_bmap obtains all delayed
              allocation extents, and does not flush dirty pages to disk
              before querying extent data. With the -v option, the flags
              column will show which extents have not yet been allocated.

       -l     If this option is used, then

                   <nblocks>  blocks

              will be appended to each line.  nblocks is the length of the
              extent described on the line in units of 512-byte blocks.

              This flag has no effect if the -v option is used.

       -n num_extents
              If this option is given, xfs_bmap obtains the extent list of
              the file in groups of num_extents extents. In the absence of
              -n, xfs_bmap queries the system for the number of extents in
              the file and uses that value to compute the group size.

       -p     If this option is used, xfs_bmap obtains all unwritten
              (preallocated) extents that do not contain written data. With
              the -v option, the flags column will show which extents are
              preallocated/unwritten.

       -v     Shows verbose information. When this flag is specified,
              additional AG specific information is appended to each line in
              the following form:

                   agno (startagoffset..endagoffset) nblocks flags

              A second -v option will print out the flags legend.

       -V     Prints the version number and exits.

SEE ALSO         top

       xfs_fsr(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, 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 2017-07-05.  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_bmap(8)

Pages that refer to this page: xfs_io(8)