1xfs_bmap(8)                 System Manager's Manual                xfs_bmap(8)
2
3
4

NAME

6       xfs_bmap - print block mapping for an XFS file
7

SYNOPSIS

9       xfs_bmap [ -adelpv ] [ -n num_extents ] file
10       xfs_bmap -V
11

DESCRIPTION

13       xfs_bmap prints the map of disk blocks used by files in an XFS filesys‐
14       tem.  The map lists each extent used by the file, as well as regions in
15       the  file that do not have any corresponding blocks (holes).  Each line
16       of the listings takes the following form:
17
18              extent: [startoffset..endoffset]: startblock..endblock
19
20       Holes are marked by replacing the startblock..endblock with hole.   All
21       the  file  offsets  and disk blocks are in units of 512-byte blocks, no
22       matter what the filesystem's block size is.
23

OPTIONS

25       -a     If this  option  is  specified,  information  about  the  file's
26              attribute fork is printed instead of the default data fork.
27
28       -d     If  portions  of  the file have been migrated offline by a DMAPI
29              application, a DMAPI read event will be generated to bring those
30              portions back online before the disk block map is printed.  How‐
31              ever if the -d option is used, no DMAPI read event will be  gen‐
32              erated for a DMAPI file and offline portions will be reported as
33              holes.
34
35       -e     If this option is used, xfs_bmap obtains all delayed  allocation
36              extents,  and does not flush dirty pages to disk before querying
37              extent data. With the -v option,  the  flags  column  will  show
38              which extents have not yet been allocated.
39
40       -l     If this option is used, then
41
42                   <nblocks>  blocks
43
44              will  be  appended  to  each line.  nblocks is the length of the
45              extent described on the line in units of 512-byte blocks.
46
47              This flag has no effect if the -v option is used.
48
49       -n num_extents
50              If  this  option  is  given,  xfs_bmap  will  display  at   most
51              num_extents extents. In the absence of -n, xfs_bmap will display
52              all extents in the file.
53
54       -p     If this option is used, xfs_bmap obtains all unwritten (preallo‐
55              cated)  extents  that  do  not contain written data. With the -v
56              option, the flags column will show which  extents  are  preallo‐
57              cated/unwritten.
58
59       -v     Shows  verbose  information.  When this flag is specified, addi‐
60              tional AG specific information is appended to each line  in  the
61              following form:
62
63                   agno (startagoffset..endagoffset) nblocks flags
64
65              A second -v option will print out the flags legend.
66
67       -V     Prints the version number and exits.
68

SEE ALSO

70       xfs_fsr(8), xfs(5).
71
72
73
74                                                                   xfs_bmap(8)
Impressum