xfs_bmap(8) System Manager's Manual xfs_bmap(8)
NAME
xfs_bmap - print block mapping for an XFS file
SYNOPSIS
xfs_bmap [ -adelpv ] [ -n num_extents ] file
xfs_bmap -V
DESCRIPTION
xfs_bmap prints the map of disk blocks used by files in an XFS filesys-
tem. 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 attri-
bute 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. How-
ever if the -d option is used, no DMAPI read event will be gen-
erated 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 ex-
tent 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 will display at most num_ex-
tents extents. In the absence of -n, xfs_bmap will display all
extents in the file.
-p If this option is used, xfs_bmap obtains all unwritten (preallo-
cated) extents that do not contain written data. With the -v op-
tion, the flags column will show which extents are preallo-
cated/unwritten.
-v Shows verbose information. When this flag is specified, addi-
tional 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).
xfs_bmap(8)