xfs_bmap - print block mapping for an XFS file
] [ -n num_extents
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:
Holes are marked by replacing the startblock
. All the file offsets and disk blocks are in units of 512-byte
blocks, no matter what the filesystem's block size is.
- If this option is specified, information about the file's attribute fork
is printed instead of the default data fork.
- 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.
- If this option is used, then
- 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.
- 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
- Shows verbose information. When this flag is specified, additional AG
specific information is appended to each line in the following form:
- A second -v option will print out the flags legend.
- Prints the version number and exits.