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. 21 22Users are encouraged to run this task on a regular basis within 23each repository to maintain good disk space utilization and good 24operating performance. 25 26Some git commands may automatically run 'git gc'; see the `--auto` flag 27below for details. If you know what you're doing and all you want is to 28disable this behavior permanently without further considerations, just do: 29 30---------------------- 31$ git config --global gc.auto 0 32---------------------- 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 Some git commands run `git gc --auto` after performing 49 operations that could create many loose objects. Housekeeping 50 is required if there are too many loose objects or too many 51 packs in the repository. 52+ 53If the number of loose objects exceeds the value of the `gc.auto` 54configuration variable, then all loose objects are combined into a 55single pack using `git repack -d -l`. Setting the value of `gc.auto` 56to 0 disables automatic packing of loose objects. 57+ 58If the number of packs exceeds the value of `gc.autoPackLimit`, 59then existing packs (except those marked with a `.keep` file 60or over `gc.bigPackThreshold` limit) 61are consolidated into a single pack by using the `-A` option of 62'git repack'. Setting `gc.autoPackLimit` to 0 disables 63automatic consolidation of packs. 64+ 65If houskeeping is required due to many loose objects or packs, all 66other housekeeping tasks (e.g. rerere, working trees, reflog...) will 67be performed as well. 68 69 70--prune=<date>:: 71 Prune loose objects older than date (default is 2 weeks ago, 72 overridable by the config variable `gc.pruneExpire`). 73 --prune=all prunes loose objects regardless of their age and 74 increases the risk of corruption if another process is writing to 75 the repository concurrently; see "NOTES" below. --prune is on by 76 default. 77 78--no-prune:: 79 Do not prune any loose objects. 80 81--quiet:: 82 Suppress all progress reports. 83 84--force:: 85 Force `git gc` to run even if there may be another `git gc` 86 instance running on this repository. 87 88--keep-largest-pack:: 89 All packs except the largest pack and those marked with a 90 `.keep` files are consolidated into a single pack. When this 91 option is used, `gc.bigPackThreshold` is ignored. 92 93Configuration 94------------- 95 96The optional configuration variable `gc.reflogExpire` can be 97set to indicate how long historical entries within each branch's 98reflog should remain available in this repository. The setting is 99expressed as a length of time, for example '90 days' or '3 months'. 100It defaults to '90 days'. 101 102The optional configuration variable `gc.reflogExpireUnreachable` 103can be set to indicate how long historical reflog entries which 104are not part of the current branch should remain available in 105this repository. These types of entries are generally created as 106a result of using `git commit --amend` or `git rebase` and are the 107commits prior to the amend or rebase occurring. Since these changes 108are not part of the current project most users will want to expire 109them sooner. This option defaults to '30 days'. 110 111The above two configuration variables can be given to a pattern. For 112example, this sets non-default expiry values only to remote-tracking 113branches: 114 115------------ 116[gc "refs/remotes/*"] 117 reflogExpire = never 118 reflogExpireUnreachable = 3 days 119------------ 120 121The optional configuration variable `gc.rerereResolved` indicates 122how long records of conflicted merge you resolved earlier are 123kept. This defaults to 60 days. 124 125The optional configuration variable `gc.rerereUnresolved` indicates 126how long records of conflicted merge you have not resolved are 127kept. This defaults to 15 days. 128 129The optional configuration variable `gc.packRefs` determines if 130'git gc' runs 'git pack-refs'. This can be set to "notbare" to enable 131it within all non-bare repos or it can be set to a boolean value. 132This defaults to true. 133 134The optional configuration variable `gc.aggressiveWindow` controls how 135much time is spent optimizing the delta compression of the objects in 136the repository when the --aggressive option is specified. The larger 137the value, the more time is spent optimizing the delta compression. See 138the documentation for the --window' option in linkgit:git-repack[1] for 139more details. This defaults to 250. 140 141Similarly, the optional configuration variable `gc.aggressiveDepth` 142controls --depth option in linkgit:git-repack[1]. This defaults to 50. 143 144The optional configuration variable `gc.pruneExpire` controls how old 145the unreferenced loose objects have to be before they are pruned. The 146default is "2 weeks ago". 147 148Optional configuration variable `gc.worktreePruneExpire` controls how 149old a stale working tree should be before `git worktree prune` deletes 150it. Default is "3 months ago". 151 152 153Notes 154----- 155 156'git gc' tries very hard not to delete objects that are referenced 157anywhere in your repository. In 158particular, it will keep not only objects referenced by your current set 159of branches and tags, but also objects referenced by the index, 160remote-tracking branches, refs saved by 'git filter-branch' in 161refs/original/, or reflogs (which may reference commits in branches 162that were later amended or rewound). 163If you are expecting some objects to be deleted and they aren't, check 164all of those locations and decide whether it makes sense in your case to 165remove those references. 166 167On the other hand, when 'git gc' runs concurrently with another process, 168there is a risk of it deleting an object that the other process is using 169but hasn't created a reference to. This may just cause the other process 170to fail or may corrupt the repository if the other process later adds a 171reference to the deleted object. Git has two features that significantly 172mitigate this problem: 173 174. Any object with modification time newer than the `--prune` date is kept, 175 along with everything reachable from it. 176 177. Most operations that add an object to the database update the 178 modification time of the object if it is already present so that #1 179 applies. 180 181However, these features fall short of a complete solution, so users who 182run commands concurrently have to live with some risk of corruption (which 183seems to be low in practice) unless they turn off automatic garbage 184collection with 'git config gc.auto 0'. 185 186HOOKS 187----- 188 189The 'git gc --auto' command will run the 'pre-auto-gc' hook. See 190linkgit:githooks[5] for more information. 191 192 193SEE ALSO 194-------- 195linkgit:git-prune[1] 196linkgit:git-reflog[1] 197linkgit:git-repack[1] 198linkgit:git-rerere[1] 199 200GIT 201--- 202Part of the linkgit:git[1] suite