| git-gc(1) |
| ========= |
| |
| NAME |
| ---- |
| git-gc - Cleanup unnecessary files and optimize the local repository |
| |
| |
| SYNOPSIS |
| -------- |
| [verse] |
| 'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force] [--keep-largest-pack] |
| |
| DESCRIPTION |
| ----------- |
| Runs a number of housekeeping tasks within the current repository, |
| such as compressing file revisions (to reduce disk space and increase |
| performance), removing unreachable objects which may have been |
| created from prior invocations of 'git add', packing refs, pruning |
| reflog, rerere metadata or stale working trees. May also update ancillary |
| indexes such as the commit-graph. |
| |
| When common porcelain operations that create objects are run, they |
| will check whether the repository has grown substantially since the |
| last maintenance, and if so run `git gc` automatically. See `gc.auto` |
| below for how to disable this behavior. |
| |
| Running `git gc` manually should only be needed when adding objects to |
| a repository without regularly running such porcelain commands, to do |
| a one-off repository optimization, or e.g. to clean up a suboptimal |
| mass-import. See the "PACKFILE OPTIMIZATION" section in |
| linkgit:git-fast-import[1] for more details on the import case. |
| |
| OPTIONS |
| ------- |
| |
| --aggressive:: |
| Usually 'git gc' runs very quickly while providing good disk |
| space utilization and performance. This option will cause |
| 'git gc' to more aggressively optimize the repository at the expense |
| of taking much more time. The effects of this optimization are |
| mostly persistent. See the "AGGRESSIVE" section below for details. |
| |
| --auto:: |
| With this option, 'git gc' checks whether any housekeeping is |
| required; if not, it exits without performing any work. |
| + |
| See the `gc.auto` option in the "CONFIGURATION" section below for how |
| this heuristic works. |
| + |
| Once housekeeping is triggered by exceeding the limits of |
| configuration options such as `gc.auto` and `gc.autoPackLimit`, all |
| other housekeeping tasks (e.g. rerere, working trees, reflog...) will |
| be performed as well. |
| |
| |
| --[no-]cruft:: |
| When expiring unreachable objects, pack them separately into a |
| cruft pack instead of storing them as loose objects. `--cruft` |
| is on by default. |
| |
| --prune=<date>:: |
| Prune loose objects older than date (default is 2 weeks ago, |
| overridable by the config variable `gc.pruneExpire`). |
| --prune=now prunes loose objects regardless of their age and |
| increases the risk of corruption if another process is writing to |
| the repository concurrently; see "NOTES" below. --prune is on by |
| default. |
| |
| --no-prune:: |
| Do not prune any loose objects. |
| |
| --quiet:: |
| Suppress all progress reports. |
| |
| --force:: |
| Force `git gc` to run even if there may be another `git gc` |
| instance running on this repository. |
| |
| --keep-largest-pack:: |
| All packs except the largest non-cruft pack, any packs marked |
| with a `.keep` file, and any cruft pack(s) are consolidated into |
| a single pack. When this option is used, `gc.bigPackThreshold` |
| is ignored. |
| |
| AGGRESSIVE |
| ---------- |
| |
| When the `--aggressive` option is supplied, linkgit:git-repack[1] will |
| be invoked with the `-f` flag, which in turn will pass |
| `--no-reuse-delta` to linkgit:git-pack-objects[1]. This will throw |
| away any existing deltas and re-compute them, at the expense of |
| spending much more time on the repacking. |
| |
| The effects of this are mostly persistent, e.g. when packs and loose |
| objects are coalesced into one another pack the existing deltas in |
| that pack might get re-used, but there are also various cases where we |
| might pick a sub-optimal delta from a newer pack instead. |
| |
| Furthermore, supplying `--aggressive` will tweak the `--depth` and |
| `--window` options passed to linkgit:git-repack[1]. See the |
| `gc.aggressiveDepth` and `gc.aggressiveWindow` settings below. By |
| using a larger window size we're more likely to find more optimal |
| deltas. |
| |
| It's probably not worth it to use this option on a given repository |
| without running tailored performance benchmarks on it. It takes a lot |
| more time, and the resulting space/delta optimization may or may not |
| be worth it. Not using this at all is the right trade-off for most |
| users and their repositories. |
| |
| CONFIGURATION |
| ------------- |
| |
| include::includes/cmd-config-section-all.txt[] |
| |
| include::config/gc.txt[] |
| |
| NOTES |
| ----- |
| |
| 'git gc' tries very hard not to delete objects that are referenced |
| anywhere in your repository. In particular, it will keep not only |
| objects referenced by your current set of branches and tags, but also |
| objects referenced by the index, remote-tracking branches, reflogs |
| (which may reference commits in branches that were later amended or |
| rewound), and anything else in the refs/* namespace. Note that a note |
| (of the kind created by 'git notes') attached to an object does not |
| contribute in keeping the object alive. If you are expecting some |
| objects to be deleted and they aren't, check all of those locations |
| and decide whether it makes sense in your case to remove those |
| references. |
| |
| On the other hand, when 'git gc' runs concurrently with another process, |
| there is a risk of it deleting an object that the other process is using |
| but hasn't created a reference to. This may just cause the other process |
| to fail or may corrupt the repository if the other process later adds a |
| reference to the deleted object. Git has two features that significantly |
| mitigate this problem: |
| |
| . Any object with modification time newer than the `--prune` date is kept, |
| along with everything reachable from it. |
| |
| . Most operations that add an object to the database update the |
| modification time of the object if it is already present so that #1 |
| applies. |
| |
| However, these features fall short of a complete solution, so users who |
| run commands concurrently have to live with some risk of corruption (which |
| seems to be low in practice). |
| |
| HOOKS |
| ----- |
| |
| The 'git gc --auto' command will run the 'pre-auto-gc' hook. See |
| linkgit:githooks[5] for more information. |
| |
| |
| SEE ALSO |
| -------- |
| linkgit:git-prune[1] |
| linkgit:git-reflog[1] |
| linkgit:git-repack[1] |
| linkgit:git-rerere[1] |
| |
| GIT |
| --- |
| Part of the linkgit:git[1] suite |