6 git-gc - Cleanup unnecessary files and optimize the local repository
12 'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force]
16 Runs a number of housekeeping tasks within the current repository,
17 such as compressing file revisions (to reduce disk space and increase
18 performance), removing unreachable objects which may have been
19 created from prior invocations of 'git add', packing refs, pruning
20 reflog, rerere metadata or stale working trees.
22 Users are encouraged to run this task on a regular basis within
23 each repository to maintain good disk space utilization and good
24 operating performance.
26 Some git commands may automatically run 'git gc'; see the `--auto` flag
27 below for details. If you know what you're doing and all you want is to
28 disable this behavior permanently without further considerations, just do:
30 ----------------------
31 $ git config --global gc.auto 0
32 ----------------------
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.
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.
53 If the number of loose objects exceeds the value of the `gc.auto`
54 configuration variable, then all loose objects are combined into a
55 single pack using `git repack -d -l`. Setting the value of `gc.auto`
56 to 0 disables automatic packing of loose objects.
58 If the number of packs exceeds the value of `gc.autoPackLimit`,
59 then existing packs (except those marked with a `.keep` file)
60 are consolidated into a single pack by using the `-A` option of
61 'git repack'. Setting `gc.autoPackLimit` to 0 disables
62 automatic consolidation of packs.
64 If houskeeping is required due to many loose objects or packs, all
65 other housekeeping tasks (e.g. rerere, working trees, reflog...) will
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
78 Do not prune any loose objects.
81 Suppress all progress reports.
84 Force `git gc` to run even if there may be another `git gc`
85 instance running on this repository.
90 The optional configuration variable `gc.reflogExpire` can be
91 set to indicate how long historical entries within each branch's
92 reflog should remain available in this repository. The setting is
93 expressed as a length of time, for example '90 days' or '3 months'.
94 It defaults to '90 days'.
96 The optional configuration variable `gc.reflogExpireUnreachable`
97 can be set to indicate how long historical reflog entries which
98 are not part of the current branch should remain available in
99 this repository. These types of entries are generally created as
100 a result of using `git commit --amend` or `git rebase` and are the
101 commits prior to the amend or rebase occurring. Since these changes
102 are not part of the current project most users will want to expire
103 them sooner. This option defaults to '30 days'.
105 The above two configuration variables can be given to a pattern. For
106 example, this sets non-default expiry values only to remote-tracking
110 [gc "refs/remotes/*"]
112 reflogExpireUnreachable = 3 days
115 The optional configuration variable `gc.rerereResolved` indicates
116 how long records of conflicted merge you resolved earlier are
117 kept. This defaults to 60 days.
119 The optional configuration variable `gc.rerereUnresolved` indicates
120 how long records of conflicted merge you have not resolved are
121 kept. This defaults to 15 days.
123 The optional configuration variable `gc.packRefs` determines if
124 'git gc' runs 'git pack-refs'. This can be set to "notbare" to enable
125 it within all non-bare repos or it can be set to a boolean value.
126 This defaults to true.
128 The optional configuration variable `gc.aggressiveWindow` controls how
129 much time is spent optimizing the delta compression of the objects in
130 the repository when the --aggressive option is specified. The larger
131 the value, the more time is spent optimizing the delta compression. See
132 the documentation for the --window' option in linkgit:git-repack[1] for
133 more details. This defaults to 250.
135 Similarly, the optional configuration variable `gc.aggressiveDepth`
136 controls --depth option in linkgit:git-repack[1]. This defaults to 50.
138 The optional configuration variable `gc.pruneExpire` controls how old
139 the unreferenced loose objects have to be before they are pruned. The
140 default is "2 weeks ago".
142 Optional configuration variable `gc.worktreePruneExpire` controls how
143 old a stale working tree should be before `git worktree prune` deletes
144 it. Default is "3 months ago".
150 'git gc' tries very hard not to delete objects that are referenced
151 anywhere in your repository. In
152 particular, it will keep not only objects referenced by your current set
153 of branches and tags, but also objects referenced by the index,
154 remote-tracking branches, refs saved by 'git filter-branch' in
155 refs/original/, or reflogs (which may reference commits in branches
156 that were later amended or rewound).
157 If you are expecting some objects to be deleted and they aren't, check
158 all of those locations and decide whether it makes sense in your case to
159 remove those references.
161 On the other hand, when 'git gc' runs concurrently with another process,
162 there is a risk of it deleting an object that the other process is using
163 but hasn't created a reference to. This may just cause the other process
164 to fail or may corrupt the repository if the other process later adds a
165 reference to the deleted object. Git has two features that significantly
166 mitigate this problem:
168 . Any object with modification time newer than the `--prune` date is kept,
169 along with everything reachable from it.
171 . Most operations that add an object to the database update the
172 modification time of the object if it is already present so that #1
175 However, these features fall short of a complete solution, so users who
176 run commands concurrently have to live with some risk of corruption (which
177 seems to be low in practice) unless they turn off automatic garbage
178 collection with 'git config gc.auto 0'.
183 The 'git gc --auto' command will run the 'pre-auto-gc' hook. See
184 linkgit:githooks[5] for more information.
190 linkgit:git-reflog[1]
191 linkgit:git-repack[1]
192 linkgit:git-rerere[1]
196 Part of the linkgit:git[1] suite