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          [--[no-]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.  This is now default; you can turn it off
  56         with --no-full.
  57
  58 --strict::
  59         Enable more strict checking, namely to catch a file mode
  60         recorded with g+w bit set, which was created by older
  61         versions of git.  Existing repositories, including the
  62         Linux kernel, git itself, and sparse repository have old
  63         objects that triggers this check, but it is recommended
  64         to check new projects with this flag.
  65
  66 --verbose::
  67         Be chatty.
  68
  69 --lost-found::
  70         Write dangling objects into .git/lost-found/commit/ or
  71         .git/lost-found/other/, depending on type.  If the object is
  72         a blob, the contents are written into the file, rather than
  73         its object name.
  74
  75 It tests SHA1 and general object sanity, and it does full tracking of
  76 the resulting reachability and everything else. It prints out any
  77 corruption it finds (missing or bad objects), and if you use the
  78 '--unreachable' flag it will also print out objects that exist but
  79 that aren't readable from any of the specified head nodes.
  80
  81 So for example
  82
  83         git fsck --unreachable HEAD \
  84                 $(git for-each-ref --format="%(objectname)" refs/heads)
  85
  86 will do quite a _lot_ of verification on the tree. There are a few
  87 extra validity tests to be added (make sure that tree objects are
  88 sorted properly etc), but on the whole if 'git fsck' is happy, you
  89 do have a valid tree.
  90
  91 Any corrupt objects you will have to find in backups or other archives
  92 (i.e., you can just remove them and do an 'rsync' with some other site in
  93 the hopes that somebody else has the object you have corrupted).
  94
  95 Of course, "valid tree" doesn't mean that it wasn't generated by some
  96 evil person, and the end result might be crap. git is a revision
  97 tracking system, not a quality assurance system ;)
  98
  99 Extracted Diagnostics
 100 ---------------------
 101
 102 expect dangling commits - potential heads - due to lack of head information::
 103         You haven't specified any nodes as heads so it won't be
 104         possible to differentiate between un-parented commits and
 105         root nodes.
 106
 107 missing sha1 directory '<dir>'::
 108         The directory holding the sha1 objects is missing.
 109
 110 unreachable <type> <object>::
 111         The <type> object <object>, isn't actually referred to directly
 112         or indirectly in any of the trees or commits seen. This can
 113         mean that there's another root node that you're not specifying
 114         or that the tree is corrupt. If you haven't missed a root node
 115         then you might as well delete unreachable nodes since they
 116         can't be used.
 117
 118 missing <type> <object>::
 119         The <type> object <object>, is referred to but isn't present in
 120         the database.
 121
 122 dangling <type> <object>::
 123         The <type> object <object>, is present in the database but never
 124         'directly' used. A dangling commit could be a root node.
 125
 126 sha1 mismatch <object>::
 127         The database has an object who's sha1 doesn't match the
 128         database value.
 129         This indicates a serious data integrity problem.
 130
 131 Environment Variables
 132 ---------------------
 133
 134 GIT_OBJECT_DIRECTORY::
 135         used to specify the object database root (usually $GIT_DIR/objects)
 136
 137 GIT_INDEX_FILE::
 138         used to specify the index file of the index
 139
 140 GIT_ALTERNATE_OBJECT_DIRECTORIES::
 141         used to specify additional object database roots (usually unset)
 142
 143 GIT
 144 ---
 145 Part of the linkgit:git[1] suite