1git-gc(1) 2========= 3 4NAME 5---- 6git-gc - Cleanup unnecessary files and optimize the local repository 7 8 9SYNOPSIS 10-------- 11[verse] 12'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force] [--keep-largest-pack] 13 14DESCRIPTION 15----------- 16Runs a number of housekeeping tasks within the current repository, 17such as compressing file revisions (to reduce disk space and increase 18performance), removing unreachable objects which may have been 19created from prior invocations of 'git add', packing refs, pruning 20reflog, rerere metadata or stale working trees. May also update ancillary 21indexes such as the commit-graph. 22 23When common porcelain operations that create objects are run, they 24will check whether the repository has grown substantially since the 25last maintenance, and if so run `git gc` automatically. See `gc.auto` 26below for how to disable this behavior. 27 28Running `git gc` manually should only be needed when adding objects to 29a repository without regularly running such porcelain commands, to do 30a one-off repository optimization, or e.g. to clean up a suboptimal 31mass-import. See the "PACKFILE OPTIMIZATION" section in 32linkgit:git-fast-import[1] for more details on the import case. 33 34OPTIONS 35------- 36 37--aggressive:: 38 Usually 'git gc' runs very quickly while providing good disk 39 space utilization and performance. This option will cause 40 'git gc' to more aggressively optimize the repository at the expense 41 of taking much more time. The effects of this optimization are 42 persistent, so this option only needs to be used occasionally; every 43 few hundred changesets or so. 44 45--auto:: 46 With this option, 'git gc' checks whether any housekeeping is 47 required; if not, it exits without performing any work. 48+ 49See the `gc.auto` option in the "CONFIGURATION" section below for how 50this heuristic works. 51+ 52Once housekeeping is triggered by exceeding the limits of 53configuration options such as `gc.auto` and `gc.autoPackLimit`, all 54other housekeeping tasks (e.g. rerere, working trees, reflog...) will 55be performed as well. 56 57 58--prune=<date>:: 59 Prune loose objects older than date (default is 2 weeks ago, 60 overridable by the config variable `gc.pruneExpire`). 61 --prune=now prunes loose objects regardless of their age and 62 increases the risk of corruption if another process is writing to 63 the repository concurrently; see "NOTES" below. --prune is on by 64 default. 65 66--no-prune:: 67 Do not prune any loose objects. 68 69--quiet:: 70 Suppress all progress reports. 71 72--force:: 73 Force `git gc` to run even if there may be another `git gc` 74 instance running on this repository. 75 76--keep-largest-pack:: 77 All packs except the largest pack and those marked with a 78 `.keep` files are consolidated into a single pack. When this 79 option is used, `gc.bigPackThreshold` is ignored. 80 81CONFIGURATION 82------------- 83 84The below documentation is the same as what's found in 85linkgit:git-config[1]: 86 87include::config/gc.txt[] 88 89NOTES 90----- 91 92'git gc' tries very hard not to delete objects that are referenced 93anywhere in your repository. In 94particular, it will keep not only objects referenced by your current set 95of branches and tags, but also objects referenced by the index, 96remote-tracking branches, refs saved by 'git filter-branch' in 97refs/original/, or reflogs (which may reference commits in branches 98that were later amended or rewound). 99If you are expecting some objects to be deleted and they aren't, check 100all of those locations and decide whether it makes sense in your case to 101remove those references. 102 103On the other hand, when 'git gc' runs concurrently with another process, 104there is a risk of it deleting an object that the other process is using 105but hasn't created a reference to. This may just cause the other process 106to fail or may corrupt the repository if the other process later adds a 107reference to the deleted object. Git has two features that significantly 108mitigate this problem: 109 110. Any object with modification time newer than the `--prune` date is kept, 111 along with everything reachable from it. 112 113. Most operations that add an object to the database update the 114 modification time of the object if it is already present so that #1 115 applies. 116 117However, these features fall short of a complete solution, so users who 118run commands concurrently have to live with some risk of corruption (which 119seems to be low in practice) unless they turn off automatic garbage 120collection with 'git config gc.auto 0'. 121 122HOOKS 123----- 124 125The 'git gc --auto' command will run the 'pre-auto-gc' hook. See 126linkgit:githooks[5] for more information. 127 128 129SEE ALSO 130-------- 131linkgit:git-prune[1] 132linkgit:git-reflog[1] 133linkgit:git-repack[1] 134linkgit:git-rerere[1] 135 136GIT 137--- 138Part of the linkgit:git[1] suite