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