xfs_bmap(8) - phpMan

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 corre-
sponding 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 num-
ber 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.