1git-fsck-cache(1) 2================= 3v0.1, May 2005 4 5NAME 6---- 7git-fsck-cache - Verifies the connectivity and validity of the objects in the database 8 9 10SYNOPSIS 11-------- 12'git-fsck-cache' [--tags] [--root] [--unreachable] [--cache] [--standalone | --full] [--strict] [<object>*] 13 14DESCRIPTION 15----------- 16Verifies the connectivity and validity of the objects in the database. 17 18OPTIONS 19------- 20<object>:: 21 An object to treat as the head of an unreachability trace. 22 23 If no objects are given, git-fsck-cache defaults to using the 24 index file and all SHA1 references in .git/refs/* as heads. 25 26--unreachable:: 27 Print out objects that exist but that aren't readable from any 28 of the reference nodes. 29 30--root:: 31 Report root nodes. 32 33--tags:: 34 Report tags. 35 36--cache:: 37 Consider any object recorded in the cache also as a head node for 38 an unreachability trace. 39 40--standalone:: 41 Limit checks to the contents of GIT_OBJECT_DIRECTORY 42 ($GIT_DIR/objects), making sure that it is consistent and 43 complete without referring to objects found in alternate 44 object pools listed in GIT_ALTERNATE_OBJECT_DIRECTORIES, 45 nor packed GIT archives found in $GIT_DIR/objects/pack; 46 cannot be used with --full. 47 48--full:: 49 Check not just objects in GIT_OBJECT_DIRECTORY 50 ($GIT_DIR/objects), but also the ones found in alternate 51 object pools listed in GIT_ALTERNATE_OBJECT_DIRECTORIES, 52 and in packed GIT archives found in $GIT_DIR/objects/pack 53 and corresponding pack subdirectories in alternate 54 object pools; cannot be used with --standalone. 55 56--strict:: 57 Enable more strict checking, namely to catch a file mode 58 recorded with g+w bit set, which was created by older 59 versions of GIT. Existing repositories, including the 60 Linux kernel, GIT itself, and sparse repository have old 61 objects that triggers this check, but it is recommended 62 to check new projects with this flag. 63 64It tests SHA1 and general object sanity, and it does full tracking of 65the resulting reachability and everything else. It prints out any 66corruption it finds (missing or bad objects), and if you use the 67'--unreachable' flag it will also print out objects that exist but 68that aren't readable from any of the specified head nodes. 69 70So for example 71 72 git-fsck-cache --unreachable $(cat .git/HEAD .git/refs/heads/*) 73 74will do quite a _lot_ of verification on the tree. There are a few 75extra validity tests to be added (make sure that tree objects are 76sorted properly etc), but on the whole if "git-fsck-cache" is happy, you 77do have a valid tree. 78 79Any corrupt objects you will have to find in backups or other archives 80(ie you can just remove them and do an "rsync" with some other site in 81the hopes that somebody else has the object you have corrupted). 82 83Of course, "valid tree" doesn't mean that it wasn't generated by some 84evil person, and the end result might be crap. Git is a revision 85tracking system, not a quality assurance system ;) 86 87Extracted Diagnostics 88--------------------- 89 90expect dangling commits - potential heads - due to lack of head information:: 91 You haven't specified any nodes as heads so it won't be 92 possible to differentiate between un-parented commits and 93 root nodes. 94 95missing sha1 directory '<dir>':: 96 The directory holding the sha1 objects is missing. 97 98unreachable <type> <object>:: 99 The <type> object <object>, isn't actually referred to directly 100 or indirectly in any of the trees or commits seen. This can 101 mean that there's another root node that you're not specifying 102 or that the tree is corrupt. If you haven't missed a root node 103 then you might as well delete unreachable nodes since they 104 can't be used. 105 106missing <type> <object>:: 107 The <type> object <object>, is referred to but isn't present in 108 the database. 109 110dangling <type> <object>:: 111 The <type> object <object>, is present in the database but never 112 'directly' used. A dangling commit could be a root node. 113 114warning: git-fsck-cache: tree <tree> has full pathnames in it:: 115 And it shouldn't... 116 117sha1 mismatch <object>:: 118 The database has an object who's sha1 doesn't match the 119 database value. 120 This indicates a serious data integrity problem. 121 122Environment Variables 123--------------------- 124 125GIT_OBJECT_DIRECTORY:: 126 used to specify the object database root (usually $GIT_DIR/objects) 127 128GIT_INDEX_FILE:: 129 used to specify the index file of the cache 130 131GIT_ALTERNATE_OBJECT_DIRECTORIES: 132 used to specify additional object database roots (usually unset) 133 134Author 135------ 136Written by Linus Torvalds <torvalds@osdl.org> 137 138Documentation 139-------------- 140Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>. 141 142GIT 143--- 144Part of the link:git.html[git] suite 145