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] 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) and removing unreachable objects which may have been 19created from prior invocations of 'git add'. 20 21Users are encouraged to run this task on a regular basis within 22each repository to maintain good disk space utilization and good 23operating performance. 24 25Some git commands may automatically run 'git gc'; see the `--auto` flag 26below for details. If you know what you're doing and all you want is to 27disable this behavior permanently without further considerations, just do: 28 29---------------------- 30$ git config --global gc.auto 0 31---------------------- 32 33OPTIONS 34------- 35 36--aggressive:: 37 Usually 'git gc' runs very quickly while providing good disk 38 space utilization and performance. This option will cause 39 'git gc' to more aggressively optimize the repository at the expense 40 of taking much more time. The effects of this optimization are 41 persistent, so this option only needs to be used occasionally; every 42 few hundred changesets or so. 43 44--auto:: 45 With this option, 'git gc' checks whether any housekeeping is 46 required; if not, it exits without performing any work. 47 Some git commands run `git gc --auto` after performing 48 operations that could create many loose objects. 49+ 50Housekeeping is required if there are too many loose objects or 51too many packs in the repository. If the number of loose objects 52exceeds the value of the `gc.auto` configuration variable, then 53all loose objects are combined into a single pack using 54`git repack -d -l`. Setting the value of `gc.auto` to 0 55disables automatic packing of loose objects. 56+ 57If the number of packs exceeds the value of `gc.autoPackLimit`, 58then existing packs (except those marked with a `.keep` file) 59are consolidated into a single pack by using the `-A` option of 60'git repack'. Setting `gc.autoPackLimit` to 0 disables 61automatic consolidation of packs. 62 63--prune=<date>:: 64 Prune loose objects older than date (default is 2 weeks ago, 65 overridable by the config variable `gc.pruneExpire`). 66 --prune=all prunes loose objects regardless of their age and 67 increases the risk of corruption if another process is writing to 68 the repository concurrently; see "NOTES" below. --prune is on by 69 default. 70 71--no-prune:: 72 Do not prune any loose objects. 73 74--quiet:: 75 Suppress all progress reports. 76 77--force:: 78 Force `git gc` to run even if there may be another `git gc` 79 instance running on this repository. 80 81Configuration 82------------- 83 84The optional configuration variable `gc.reflogExpire` can be 85set to indicate how long historical entries within each branch's 86reflog should remain available in this repository. The setting is 87expressed as a length of time, for example '90 days' or '3 months'. 88It defaults to '90 days'. 89 90The optional configuration variable `gc.reflogExpireUnreachable` 91can be set to indicate how long historical reflog entries which 92are not part of the current branch should remain available in 93this repository. These types of entries are generally created as 94a result of using `git commit --amend` or `git rebase` and are the 95commits prior to the amend or rebase occurring. Since these changes 96are not part of the current project most users will want to expire 97them sooner. This option defaults to '30 days'. 98 99The above two configuration variables can be given to a pattern. For 100example, this sets non-default expiry values only to remote-tracking 101branches: 102 103------------ 104[gc "refs/remotes/*"] 105 reflogExpire = never 106 reflogExpireUnreachable = 3 days 107------------ 108 109The optional configuration variable `gc.rerereResolved` indicates 110how long records of conflicted merge you resolved earlier are 111kept. This defaults to 60 days. 112 113The optional configuration variable `gc.rerereUnresolved` indicates 114how long records of conflicted merge you have not resolved are 115kept. This defaults to 15 days. 116 117The optional configuration variable `gc.packRefs` determines if 118'git gc' runs 'git pack-refs'. This can be set to "notbare" to enable 119it within all non-bare repos or it can be set to a boolean value. 120This defaults to true. 121 122The optional configuration variable `gc.aggressiveWindow` controls how 123much time is spent optimizing the delta compression of the objects in 124the repository when the --aggressive option is specified. The larger 125the value, the more time is spent optimizing the delta compression. See 126the documentation for the --window' option in linkgit:git-repack[1] for 127more details. This defaults to 250. 128 129Similarly, the optional configuration variable `gc.aggressiveDepth` 130controls --depth option in linkgit:git-repack[1]. This defaults to 250. 131 132The optional configuration variable `gc.pruneExpire` controls how old 133the unreferenced loose objects have to be before they are pruned. The 134default is "2 weeks ago". 135 136 137Notes 138----- 139 140'git gc' tries very hard not to delete objects that are referenced 141anywhere in your repository. In 142particular, it will keep not only objects referenced by your current set 143of branches and tags, but also objects referenced by the index, 144remote-tracking branches, refs saved by 'git filter-branch' in 145refs/original/, or reflogs (which may reference commits in branches 146that were later amended or rewound). 147If you are expecting some objects to be deleted and they aren't, check 148all of those locations and decide whether it makes sense in your case to 149remove those references. 150 151On the other hand, when 'git gc' runs concurrently with another process, 152there is a risk of it deleting an object that the other process is using 153but hasn't created a reference to. This may just cause the other process 154to fail or may corrupt the repository if the other process later adds a 155reference to the deleted object. Git has two features that significantly 156mitigate this problem: 157 158. Any object with modification time newer than the `--prune` date is kept, 159 along with everything reachable from it. 160 161. Most operations that add an object to the database update the 162 modification time of the object if it is already present so that #1 163 applies. 164 165However, these features fall short of a complete solution, so users who 166run commands concurrently have to live with some risk of corruption (which 167seems to be low in practice) unless they turn off automatic garbage 168collection with 'git config gc.auto 0'. 169 170HOOKS 171----- 172 173The 'git gc --auto' command will run the 'pre-auto-gc' hook. See 174linkgit:githooks[5] for more information. 175 176 177SEE ALSO 178-------- 179linkgit:git-prune[1] 180linkgit:git-reflog[1] 181linkgit:git-repack[1] 182linkgit:git-rerere[1] 183 184GIT 185--- 186Part of the linkgit:git[1] suite