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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SEE ALSO | COLOPHON |
xfs_bmap(8) System Manager's Manual xfs_bmap(8)
xfs_bmap - print block mapping for an XFS file
xfs_bmap [ -adlpv ] [ -n num_extents ] file
xfs_bmap -V
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.
-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.
xfs_fsr(8), xfs(5).
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)