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 [--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. 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 74It tests SHA1 and general object sanity, and it does full tracking of 75the resulting reachability and everything else. It prints out any 76corruption it finds (missing or bad objects), and if you use the 77'--unreachable' flag it will also print out objects that exist but 78that aren't readable from any of the specified head nodes. 79 80So for example 81 82 git fsck --unreachable HEAD \ 83 $(git for-each-ref --format="%(objectname)" refs/heads) 84 85will do quite a _lot_ of verification on the tree. There are a few 86extra validity tests to be added (make sure that tree objects are 87sorted properly etc), but on the whole if 'git-fsck' is happy, you 88do have a valid tree. 89 90Any corrupt objects you will have to find in backups or other archives 91(i.e., you can just remove them and do an 'rsync' with some other site in 92the hopes that somebody else has the object you have corrupted). 93 94Of course, "valid tree" doesn't mean that it wasn't generated by some 95evil person, and the end result might be crap. git is a revision 96tracking system, not a quality assurance system ;) 97 98Extracted Diagnostics 99--------------------- 100 101expect dangling commits - potential heads - due to lack of head information:: 102 You haven't specified any nodes as heads so it won't be 103 possible to differentiate between un-parented commits and 104 root nodes. 105 106missing sha1 directory '<dir>':: 107 The directory holding the sha1 objects is missing. 108 109unreachable <type> <object>:: 110 The <type> object <object>, isn't actually referred to directly 111 or indirectly in any of the trees or commits seen. This can 112 mean that there's another root node that you're not specifying 113 or that the tree is corrupt. If you haven't missed a root node 114 then you might as well delete unreachable nodes since they 115 can't be used. 116 117missing <type> <object>:: 118 The <type> object <object>, is referred to but isn't present in 119 the database. 120 121dangling <type> <object>:: 122 The <type> object <object>, is present in the database but never 123 'directly' used. A dangling commit could be a root node. 124 125warning: git-fsck: tree <tree> has full pathnames in it:: 126 And it shouldn't... 127 128sha1 mismatch <object>:: 129 The database has an object who's sha1 doesn't match the 130 database value. 131 This indicates a serious data integrity problem. 132 133Environment Variables 134--------------------- 135 136GIT_OBJECT_DIRECTORY:: 137 used to specify the object database root (usually $GIT_DIR/objects) 138 139GIT_INDEX_FILE:: 140 used to specify the index file of the index 141 142GIT_ALTERNATE_OBJECT_DIRECTORIES:: 143 used to specify additional object database roots (usually unset) 144 145Author 146------ 147Written by Linus Torvalds <torvalds@osdl.org> 148 149Documentation 150-------------- 151Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>. 152 153GIT 154--- 155Part of the linkgit:git[1] suite