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 reachable 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 reachable 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 126sha1 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 131Environment Variables 132--------------------- 133 134GIT_OBJECT_DIRECTORY:: 135 used to specify the object database root (usually $GIT_DIR/objects) 136 137GIT_INDEX_FILE:: 138 used to specify the index file of the index 139 140GIT_ALTERNATE_OBJECT_DIRECTORIES:: 141 used to specify additional object database roots (usually unset) 142 143GIT 144--- 145Part of the linkgit:git[1] suite