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



NAME
       xfs_bmap - print block mapping for an XFS file

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

DESCRIPTION
       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
       -a     If this option is specified, information about the file's attribute 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.

       -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 writ‐
              ten 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
       xfs_fsr(8), xfs(5).