Documentation / git-fsck.txton commit merge-recursive --renormalize (7610fa5)
   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] [--no-reflogs]
  13         [--[no-]full] [--strict] [--verbose] [--lost-found] [<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, 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
  75It tests SHA1 and general object sanity, and it does full tracking of
  76the resulting reachability and everything else. It prints out any
  77corruption it finds (missing or bad objects), and if you use the
  78'--unreachable' flag it will also print out objects that exist but
  79that aren't readable from any of the specified head nodes.
  80
  81So for example
  82
  83        git fsck --unreachable HEAD \
  84                $(git for-each-ref --format="%(objectname)" refs/heads)
  85
  86will do quite a _lot_ of verification on the tree. There are a few
  87extra validity tests to be added (make sure that tree objects are
  88sorted properly etc), but on the whole if 'git fsck' is happy, you
  89do have a valid tree.
  90
  91Any 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
  93the hopes that somebody else has the object you have corrupted).
  94
  95Of course, "valid tree" doesn't mean that it wasn't generated by some
  96evil person, and the end result might be crap. git is a revision
  97tracking system, not a quality assurance system ;)
  98
  99Extracted Diagnostics
 100---------------------
 101
 102expect 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
 107missing sha1 directory '<dir>'::
 108        The directory holding the sha1 objects is missing.
 109
 110unreachable <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
 118missing <type> <object>::
 119        The <type> object <object>, is referred to but isn't present in
 120        the database.
 121
 122dangling <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
 126warning: git-fsck: tree <tree> has full pathnames in it::
 127        And it shouldn't...
 128
 129sha1 mismatch <object>::
 130        The database has an object who's sha1 doesn't match the
 131        database value.
 132        This indicates a serious data integrity problem.
 133
 134Environment Variables
 135---------------------
 136
 137GIT_OBJECT_DIRECTORY::
 138        used to specify the object database root (usually $GIT_DIR/objects)
 139
 140GIT_INDEX_FILE::
 141        used to specify the index file of the index
 142
 143GIT_ALTERNATE_OBJECT_DIRECTORIES::
 144        used to specify additional object database roots (usually unset)
 145
 146Author
 147------
 148Written by Linus Torvalds <torvalds@osdl.org>
 149
 150Documentation
 151--------------
 152Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 153
 154GIT
 155---
 156Part of the linkgit:git[1] suite