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) 60are consolidated into a single pack by using the `-A` option of 61'git repack'. Setting `gc.autoPackLimit` to 0 disables 62automatic consolidation of packs. 63+ 64If houskeeping is required due to many loose objects or packs, all 65other housekeeping tasks (e.g. rerere, working trees, reflog...) will 66be performed as well. 67 68 69--prune=<date>:: 70 Prune loose objects older than date (default is 2 weeks ago, 71 overridable by the config variable `gc.pruneExpire`). 72 --prune=all prunes loose objects regardless of their age and 73 increases the risk of corruption if another process is writing to 74 the repository concurrently; see "NOTES" below. --prune is on by 75 default. 76 77--no-prune:: 78 Do not prune any loose objects. 79 80--quiet:: 81 Suppress all progress reports. 82 83--force:: 84 Force `git gc` to run even if there may be another `git gc` 85 instance running on this repository. 86 87--keep-largest-pack:: 88 All packs except the largest pack and those marked with a 89 `.keep` files are consolidated into a single pack. 90 91Configuration 92------------- 93 94The optional configuration variable `gc.reflogExpire` can be 95set to indicate how long historical entries within each branch's 96reflog should remain available in this repository. The setting is 97expressed as a length of time, for example '90 days' or '3 months'. 98It defaults to '90 days'. 99 100The optional configuration variable `gc.reflogExpireUnreachable` 101can be set to indicate how long historical reflog entries which 102are not part of the current branch should remain available in 103this repository. These types of entries are generally created as 104a result of using `git commit --amend` or `git rebase` and are the 105commits prior to the amend or rebase occurring. Since these changes 106are not part of the current project most users will want to expire 107them sooner. This option defaults to '30 days'. 108 109The above two configuration variables can be given to a pattern. For 110example, this sets non-default expiry values only to remote-tracking 111branches: 112 113------------ 114[gc "refs/remotes/*"] 115 reflogExpire = never 116 reflogExpireUnreachable = 3 days 117------------ 118 119The optional configuration variable `gc.rerereResolved` indicates 120how long records of conflicted merge you resolved earlier are 121kept. This defaults to 60 days. 122 123The optional configuration variable `gc.rerereUnresolved` indicates 124how long records of conflicted merge you have not resolved are 125kept. This defaults to 15 days. 126 127The optional configuration variable `gc.packRefs` determines if 128'git gc' runs 'git pack-refs'. This can be set to "notbare" to enable 129it within all non-bare repos or it can be set to a boolean value. 130This defaults to true. 131 132The optional configuration variable `gc.aggressiveWindow` controls how 133much time is spent optimizing the delta compression of the objects in 134the repository when the --aggressive option is specified. The larger 135the value, the more time is spent optimizing the delta compression. See 136the documentation for the --window' option in linkgit:git-repack[1] for 137more details. This defaults to 250. 138 139Similarly, the optional configuration variable `gc.aggressiveDepth` 140controls --depth option in linkgit:git-repack[1]. This defaults to 50. 141 142The optional configuration variable `gc.pruneExpire` controls how old 143the unreferenced loose objects have to be before they are pruned. The 144default is "2 weeks ago". 145 146Optional configuration variable `gc.worktreePruneExpire` controls how 147old a stale working tree should be before `git worktree prune` deletes 148it. Default is "3 months ago". 149 150 151Notes 152----- 153 154'git gc' tries very hard not to delete objects that are referenced 155anywhere in your repository. In 156particular, it will keep not only objects referenced by your current set 157of branches and tags, but also objects referenced by the index, 158remote-tracking branches, refs saved by 'git filter-branch' in 159refs/original/, or reflogs (which may reference commits in branches 160that were later amended or rewound). 161If you are expecting some objects to be deleted and they aren't, check 162all of those locations and decide whether it makes sense in your case to 163remove those references. 164 165On the other hand, when 'git gc' runs concurrently with another process, 166there is a risk of it deleting an object that the other process is using 167but hasn't created a reference to. This may just cause the other process 168to fail or may corrupt the repository if the other process later adds a 169reference to the deleted object. Git has two features that significantly 170mitigate this problem: 171 172. Any object with modification time newer than the `--prune` date is kept, 173 along with everything reachable from it. 174 175. Most operations that add an object to the database update the 176 modification time of the object if it is already present so that #1 177 applies. 178 179However, these features fall short of a complete solution, so users who 180run commands concurrently have to live with some risk of corruption (which 181seems to be low in practice) unless they turn off automatic garbage 182collection with 'git config gc.auto 0'. 183 184HOOKS 185----- 186 187The 'git gc --auto' command will run the 'pre-auto-gc' hook. See 188linkgit:githooks[5] for more information. 189 190 191SEE ALSO 192-------- 193linkgit:git-prune[1] 194linkgit:git-reflog[1] 195linkgit:git-repack[1] 196linkgit:git-rerere[1] 197 198GIT 199--- 200Part of the linkgit:git[1] suite