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