1xfs_metadump(8) System Manager's Manual xfs_metadump(8)
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6 xfs_metadump - copy XFS filesystem metadata to a file
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9 xfs_metadump [ -aefFgow ] [ -m max_extents ] ] [ -l logdev ] source
10 target
11 xfs_metadump -V
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14 xfs_metadump is a debugging tool that copies the metadata from an XFS
15 filesystem to a file. The source argument must be the pathname of the
16 device or file containing the XFS filesystem and the target argument
17 specifies the destination file name. If target is -, then the output
18 is sent to stdout. This allows the output to be redirected to another
19 program such as a compression application.
20 xfs_metadump may only be used to copy unmounted filesystems, or read-
22 only mounted filesystems.
23 xfs_metadump does not alter the source filesystem in any way. The tar‐
25 get image is a contiguous (non-sparse) file containing all the filesys‐
26 tem's metadata and indexes to where the blocks were copied from.
27 By default, xfs_metadump obfuscates most file (regular file, directory
29 and symbolic link) names and extended attribute names to allow the
30 dumps to be sent without revealing confidential information. Extended
31 attribute values are zeroed and no data is copied. The only exceptions
32 are file or attribute names that are 4 or less characters in length.
33 Also file names that span extents (this can only occur with the
34 mkfs.xfs(8) options where -n size > -b size) are not obfuscated. Names
35 between 5 and 8 characters in length inclusively are partially obfus‐
36 cated.
37 xfs_metadump should not be used for any purposes other than for debug‐
39 ging and reporting filesystem problems. The most common usage scenario
40 for this tool is when xfs_repair(8) fails to repair a filesystem and a
41 metadump image can be sent for analysis.
42 The file generated by xfs_metadump can be restored to filesystem image
44 (minus the data) using the xfs_mdrestore(8) tool.
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47 -a Copies entire metadata blocks. Normally, xfs_metadump will zero
48 any stale bytes interspersed with in-use metadata. Use this
49 option to copy full metadata blocks, to provide more debugging
50 information for a corrupted filesystem. Note that the extra
51 data will be unobfuscated.
52 -e Stops the dump on a read error. Normally, it will ignore read
54 errors and copy all the metadata that is accessible.
55 -f Specifies that the filesystem image to be processed is stored in
57 a regular file (see the mkfs.xfs -d file option). This can also
58 happen if an image copy of a filesystem has been made into an
59 ordinary file with xfs_copy(8).
60 -F Specifies that we want to continue even if the superblock magic
62 is not correct. If the source is truly not an XFS filesystem,
63 the resulting image will be useless, and xfs_metadump may crash.
64 -g Shows dump progress. This is sent to stdout if the target is a
66 file or to stderr if the target is stdout.
67 -l logdev
69 For filesystems which use an external log, this specifies the
70 device where the external log resides. The external log is not
71 copied, only internal logs are copied.
72 -m Set the maximum size of an allowed metadata extent. Extremely
74 large metadata extents are likely to be corrupt, and will be
75 skipped if they exceed this value. The default size is 2097151
76 blocks.
77 -o Disables obfuscation of file names and extended attributes.
79 -w Prints warnings of inconsistent metadata encountered to stderr.
81 Bad metadata is still copied.
82 -V Prints the version number and exits.
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86 xfs_metadump returns an exit code of 0 if all readable metadata is suc‐
87 cessfully copied or 1 if a write error occurs or a read error occurs
88 and the -e option used.
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91 As xfs_metadump copies metadata only, it does not matter if the source
92 filesystem has a realtime section or not. If the filesystem has an
93 external log, it is not copied. Internal logs are copied and any out‐
94 standing log transactions are not obfuscated if they contain names.
95 xfs_metadump is a shell wrapper around the xfs_db(8) metadump command.
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99 xfs_repair(8), xfs_mdrestore(8), xfs_freeze(8), xfs_db(8), xfs_copy(8),
100 xfs(5)
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103 Email bug reports to linux-xfs@vger.kernel.org.
104 xfs_metadump(8)