1xfs_bmap(8) System Manager's Manual xfs_bmap(8)
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6 xfs_bmap - print block mapping for an XFS file
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9 xfs_bmap [ -adlpv ] [ -n num_extents ] file
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12 xfs_bmap prints the map of disk blocks used by files in an XFS filesys‐
13 tem. The map lists each extent used by the file, as well as regions in
14 the file that do not have any corresponding blocks (holes). Each line
15 of the listings takes the following form:
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17 extent: [startoffset..endoffset]: startblock..endblock
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19 Holes are marked by replacing the startblock..endblock with hole. All
20 the file offsets and disk blocks are in units of 512-byte blocks, no
21 matter what the filesystem's block size is.
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24 -a If this option is specified, information about the file's
25 attribute fork is printed instead of the default data fork.
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27 -d If portions of the file have been migrated offline by a DMAPI
28 application, a DMAPI read event will be generated to bring those
29 portions back online before the disk block map is printed. How‐
30 ever if the -d option is used, no DMAPI read event will be gen‐
31 erated for a DMAPI file and offline portions will be reported as
32 holes.
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34 -l If this option is used, then
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36 <nblocks> blocks
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38 will be appended to each line. nblocks is the length of the
39 extent described on the line in units of 512-byte blocks.
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41 This flag has no effect if the -v option is used.
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43 -n num_extents
44 If this option is given, xfs_bmap obtains the extent list of the
45 file in groups of num_extents extents. In the absence of -n,
46 xfs_bmap queries the system for the number of extents in the
47 file and uses that value to compute the group size.
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49 -p If this option is used, xfs_bmap obtains all unwritten (preallo‐
50 cated) extents that do not contain written data. With the -v
51 option, the flags column will show which extents are preallo‐
52 cated/unwritten.
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54 -v Shows verbose information. When this flag is specified, addi‐
55 tional AG specific information is appended to each line in the
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58 agno (startagoffset..endagoffset) nblocks flags
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60 A second -v option will print out the flags legend.
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63 xfs_fsr(8), xfs(5).
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67 xfs_bmap(8)