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1 | git-gc(1) | |
2 | ========= | |
3 | ||
4 | NAME | |
5 | ---- | |
6 | git-gc - Cleanup unnecessary files and optimize the local repository | |
7 | ||
8 | ||
9 | SYNOPSIS | |
10 | -------- | |
11 | [verse] | |
12 | 'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force] [--keep-largest-pack] | |
13 | ||
14 | DESCRIPTION | |
15 | ----------- | |
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. May also update ancillary | |
21 | indexes such as the commit-graph. | |
22 | ||
23 | When common porcelain operations that create objects are run, they | |
24 | will check whether the repository has grown substantially since the | |
25 | last maintenance, and if so run `git gc` automatically. See `gc.auto` | |
26 | below for how to disable this behavior. | |
27 | ||
28 | Running `git gc` manually should only be needed when adding objects to | |
29 | a repository without regularly running such porcelain commands, to do | |
30 | a one-off repository optimization, or e.g. to clean up a suboptimal | |
31 | mass-import. See the "PACKFILE OPTIMIZATION" section in | |
32 | linkgit:git-fast-import[1] for more details on the import case. | |
33 | ||
34 | OPTIONS | |
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 | mostly persistent. See the "AGGRESSIVE" section below for details. | |
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 | + | |
48 | See the `gc.auto` option in the "CONFIGURATION" section below for how | |
49 | this heuristic works. | |
50 | + | |
51 | Once housekeeping is triggered by exceeding the limits of | |
52 | configuration options such as `gc.auto` and `gc.autoPackLimit`, all | |
53 | other housekeeping tasks (e.g. rerere, working trees, reflog...) will | |
54 | be performed as well. | |
55 | ||
56 | ||
57 | --prune=<date>:: | |
58 | Prune loose objects older than date (default is 2 weeks ago, | |
59 | overridable by the config variable `gc.pruneExpire`). | |
60 | --prune=now prunes loose objects regardless of their age and | |
61 | increases the risk of corruption if another process is writing to | |
62 | the repository concurrently; see "NOTES" below. --prune is on by | |
63 | default. | |
64 | ||
65 | --no-prune:: | |
66 | Do not prune any loose objects. | |
67 | ||
68 | --quiet:: | |
69 | Suppress all progress reports. | |
70 | ||
71 | --force:: | |
72 | Force `git gc` to run even if there may be another `git gc` | |
73 | instance running on this repository. | |
74 | ||
75 | --keep-largest-pack:: | |
76 | All packs except the largest pack and those marked with a | |
77 | `.keep` files are consolidated into a single pack. When this | |
78 | option is used, `gc.bigPackThreshold` is ignored. | |
79 | ||
80 | AGGRESSIVE | |
81 | ---------- | |
82 | ||
83 | When the `--aggressive` option is supplied, linkgit:git-repack[1] will | |
84 | be invoked with the `-f` flag, which in turn will pass | |
85 | `--no-reuse-delta` to linkgit:git-pack-objects[1]. This will throw | |
86 | away any existing deltas and re-compute them, at the expense of | |
87 | spending much more time on the repacking. | |
88 | ||
89 | The effects of this are mostly persistent, e.g. when packs and loose | |
90 | objects are coalesced into one another pack the existing deltas in | |
91 | that pack might get re-used, but there are also various cases where we | |
92 | might pick a sub-optimal delta from a newer pack instead. | |
93 | ||
94 | Furthermore, supplying `--aggressive` will tweak the `--depth` and | |
95 | `--window` options passed to linkgit:git-repack[1]. See the | |
96 | `gc.aggressiveDepth` and `gc.aggressiveWindow` settings below. By | |
97 | using a larger window size we're more likely to find more optimal | |
98 | deltas. | |
99 | ||
100 | It's probably not worth it to use this option on a given repository | |
101 | without running tailored performance benchmarks on it. It takes a lot | |
102 | more time, and the resulting space/delta optimization may or may not | |
103 | be worth it. Not using this at all is the right trade-off for most | |
104 | users and their repositories. | |
105 | ||
106 | CONFIGURATION | |
107 | ------------- | |
108 | ||
109 | The below documentation is the same as what's found in | |
110 | linkgit:git-config[1]: | |
111 | ||
112 | include::config/gc.txt[] | |
113 | ||
114 | NOTES | |
115 | ----- | |
116 | ||
117 | 'git gc' tries very hard not to delete objects that are referenced | |
118 | anywhere in your repository. In particular, it will keep not only | |
119 | objects referenced by your current set of branches and tags, but also | |
120 | objects referenced by the index, remote-tracking branches, notes saved | |
121 | by 'git notes' under refs/notes/, reflogs (which may reference commits | |
122 | in branches that were later amended or rewound), and anything else in | |
123 | the refs/* namespace. If you are expecting some objects to be deleted | |
124 | and they aren't, check all of those locations and decide whether it | |
125 | makes sense in your case to remove those references. | |
126 | ||
127 | On the other hand, when 'git gc' runs concurrently with another process, | |
128 | there is a risk of it deleting an object that the other process is using | |
129 | but hasn't created a reference to. This may just cause the other process | |
130 | to fail or may corrupt the repository if the other process later adds a | |
131 | reference to the deleted object. Git has two features that significantly | |
132 | mitigate this problem: | |
133 | ||
134 | . Any object with modification time newer than the `--prune` date is kept, | |
135 | along with everything reachable from it. | |
136 | ||
137 | . Most operations that add an object to the database update the | |
138 | modification time of the object if it is already present so that #1 | |
139 | applies. | |
140 | ||
141 | However, these features fall short of a complete solution, so users who | |
142 | run commands concurrently have to live with some risk of corruption (which | |
143 | seems to be low in practice). | |
144 | ||
145 | HOOKS | |
146 | ----- | |
147 | ||
148 | The 'git gc --auto' command will run the 'pre-auto-gc' hook. See | |
149 | linkgit:githooks[5] for more information. | |
150 | ||
151 | ||
152 | SEE ALSO | |
153 | -------- | |
154 | linkgit:git-prune[1] | |
155 | linkgit:git-reflog[1] | |
156 | linkgit:git-repack[1] | |
157 | linkgit:git-rerere[1] | |
158 | ||
159 | GIT | |
160 | --- | |
161 | Part of the linkgit:git[1] suite |