d5a76472196a5e67bc6e62411d90377ec3b46e3a
[git/git.git] / Documentation / git-fsck.txt
1 git-fsck(1)
2 ===========
3
4 NAME
5 ----
6 git-fsck - Verifies the connectivity and validity of the objects in the database
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git fsck' [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
13 [--full] [--strict] [--verbose] [--lost-found] [<object>*]
14
15 DESCRIPTION
16 -----------
17 Verifies the connectivity and validity of the objects in the database.
18
19 OPTIONS
20 -------
21 <object>::
22 An object to treat as the head of an unreachability trace.
23 +
24 If no objects are given, 'git-fsck' defaults to using the
25 index file, all SHA1 references in .git/refs/*, and all reflogs (unless
26 --no-reflogs is given) as heads.
27
28 --unreachable::
29 Print out objects that exist but that aren't readable from any
30 of the reference nodes.
31
32 --root::
33 Report root nodes.
34
35 --tags::
36 Report tags.
37
38 --cache::
39 Consider any object recorded in the index also as a head node for
40 an unreachability trace.
41
42 --no-reflogs::
43 Do not consider commits that are referenced only by an
44 entry in a reflog to be reachable. This option is meant
45 only to search for commits that used to be in a ref, but
46 now aren't, but are still in that corresponding reflog.
47
48 --full::
49 Check not just objects in GIT_OBJECT_DIRECTORY
50 ($GIT_DIR/objects), but also the ones found in alternate
51 object pools listed in GIT_ALTERNATE_OBJECT_DIRECTORIES
52 or $GIT_DIR/objects/info/alternates,
53 and in packed git archives found in $GIT_DIR/objects/pack
54 and corresponding pack subdirectories in alternate
55 object pools.
56
57 --strict::
58 Enable more strict checking, namely to catch a file mode
59 recorded with g+w bit set, which was created by older
60 versions of git. Existing repositories, including the
61 Linux kernel, git itself, and sparse repository have old
62 objects that triggers this check, but it is recommended
63 to check new projects with this flag.
64
65 --verbose::
66 Be chatty.
67
68 --lost-found::
69 Write dangling objects into .git/lost-found/commit/ or
70 .git/lost-found/other/, depending on type. If the object is
71 a blob, the contents are written into the file, rather than
72 its object name.
73
74 It tests SHA1 and general object sanity, and it does full tracking of
75 the resulting reachability and everything else. It prints out any
76 corruption it finds (missing or bad objects), and if you use the
77 '--unreachable' flag it will also print out objects that exist but
78 that aren't readable from any of the specified head nodes.
79
80 So for example
81
82 git fsck --unreachable HEAD $(cat .git/refs/heads/*)
83
84 will do quite a _lot_ of verification on the tree. There are a few
85 extra validity tests to be added (make sure that tree objects are
86 sorted properly etc), but on the whole if 'git-fsck' is happy, you
87 do have a valid tree.
88
89 Any corrupt objects you will have to find in backups or other archives
90 (i.e., you can just remove them and do an 'rsync' with some other site in
91 the hopes that somebody else has the object you have corrupted).
92
93 Of course, "valid tree" doesn't mean that it wasn't generated by some
94 evil person, and the end result might be crap. git is a revision
95 tracking system, not a quality assurance system ;)
96
97 Extracted Diagnostics
98 ---------------------
99
100 expect dangling commits - potential heads - due to lack of head information::
101 You haven't specified any nodes as heads so it won't be
102 possible to differentiate between un-parented commits and
103 root nodes.
104
105 missing sha1 directory '<dir>'::
106 The directory holding the sha1 objects is missing.
107
108 unreachable <type> <object>::
109 The <type> object <object>, isn't actually referred to directly
110 or indirectly in any of the trees or commits seen. This can
111 mean that there's another root node that you're not specifying
112 or that the tree is corrupt. If you haven't missed a root node
113 then you might as well delete unreachable nodes since they
114 can't be used.
115
116 missing <type> <object>::
117 The <type> object <object>, is referred to but isn't present in
118 the database.
119
120 dangling <type> <object>::
121 The <type> object <object>, is present in the database but never
122 'directly' used. A dangling commit could be a root node.
123
124 warning: git-fsck: tree <tree> has full pathnames in it::
125 And it shouldn't...
126
127 sha1 mismatch <object>::
128 The database has an object who's sha1 doesn't match the
129 database value.
130 This indicates a serious data integrity problem.
131
132 Environment Variables
133 ---------------------
134
135 GIT_OBJECT_DIRECTORY::
136 used to specify the object database root (usually $GIT_DIR/objects)
137
138 GIT_INDEX_FILE::
139 used to specify the index file of the index
140
141 GIT_ALTERNATE_OBJECT_DIRECTORIES::
142 used to specify additional object database roots (usually unset)
143
144 Author
145 ------
146 Written by Linus Torvalds <torvalds@osdl.org>
147
148 Documentation
149 --------------
150 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
151
152 GIT
153 ---
154 Part of the linkgit:git[1] suite