GIT-GC(1)                        Git Manual                        GIT-GC(1)

NAME         top

       git-gc - Cleanup unnecessary files and optimize the local repository

SYNOPSIS         top

       git gc [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force] [--keep-largest-pack]

DESCRIPTION         top

       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.

       Users are encouraged to run this task on a regular basis within each
       repository to maintain good disk space utilization and good operating

       Some git commands may automatically run git gc; see the --auto flag
       below for details. If you know what you’re doing and all you want is
       to disable this behavior permanently without further considerations,
       just do:

           $ git config --global 0

OPTIONS         top

           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
           persistent, so this option only needs to be used occasionally;
           every few hundred changesets or so.

           With this option, git gc checks whether any housekeeping is
           required; if not, it exits without performing any work. Some git
           commands run git gc --auto after performing operations that could
           create many loose objects. Housekeeping is required if there are
           too many loose objects or too many packs in the repository.

           If the number of loose objects exceeds the value of the
           configuration variable, then all loose objects are combined into
           a single pack using git repack -d -l. Setting the value of
  to 0 disables automatic packing of loose objects.

           If the number of packs exceeds the value of gc.autoPackLimit,
           then existing packs (except those marked with a .keep file or
           over gc.bigPackThreshold limit) are consolidated into a single
           pack by using the -A option of git repack. If the amount of
           memory is estimated not enough for git repack to run smoothly and
           gc.bigPackThreshold is not set, the largest pack will also be
           excluded (this is the equivalent of running git gc with
           --keep-base-pack). Setting gc.autoPackLimit to 0 disables
           automatic consolidation of packs.

           If houskeeping is required due to many loose objects or packs,
           all other housekeeping tasks (e.g. rerere, working trees,
           reflog...) will be performed as well.

           Prune loose objects older than date (default is 2 weeks ago,
           overridable by the config variable gc.pruneExpire). --prune=all
           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

           Do not prune any loose objects.

           Suppress all progress reports.

           Force git gc to run even if there may be another git gc instance
           running on this repository.

           All packs except the largest pack and those marked with a .keep
           files are consolidated into a single pack. When this option is
           used, gc.bigPackThreshold is ignored.


       The optional configuration variable gc.reflogExpire can be set to
       indicate how long historical entries within each branch’s reflog
       should remain available in this repository. The setting is expressed
       as a length of time, for example 90 days or 3 months. It defaults to
       90 days.

       The optional configuration variable gc.reflogExpireUnreachable can be
       set to indicate how long historical reflog entries which are not part
       of the current branch should remain available in this repository.
       These types of entries are generally created as a result of using git
       commit --amend or git rebase and are the commits prior to the amend
       or rebase occurring. Since these changes are not part of the current
       project most users will want to expire them sooner. This option
       defaults to 30 days.

       The above two configuration variables can be given to a pattern. For
       example, this sets non-default expiry values only to remote-tracking

           [gc "refs/remotes/*"]
                   reflogExpire = never
                   reflogExpireUnreachable = 3 days

       The optional configuration variable gc.rerereResolved indicates how
       long records of conflicted merge you resolved earlier are kept. This
       defaults to 60 days.

       The optional configuration variable gc.rerereUnresolved indicates how
       long records of conflicted merge you have not resolved are kept. This
       defaults to 15 days.

       The optional configuration variable gc.packRefs determines if git gc
       runs git pack-refs. This can be set to "notbare" to enable it within
       all non-bare repos or it can be set to a boolean value. This defaults
       to true.

       The optional configuration variable gc.commitGraph determines if git
       gc should run git commit-graph write. This can be set to a boolean
       value. This defaults to false.

       The optional configuration variable gc.aggressiveWindow controls how
       much time is spent optimizing the delta compression of the objects in
       the repository when the --aggressive option is specified. The larger
       the value, the more time is spent optimizing the delta compression.
       See the documentation for the --window option in git-repack(1) for
       more details. This defaults to 250.

       Similarly, the optional configuration variable gc.aggressiveDepth
       controls --depth option in git-repack(1). This defaults to 50.

       The optional configuration variable gc.pruneExpire controls how old
       the unreferenced loose objects have to be before they are pruned. The
       default is "2 weeks ago".

       Optional configuration variable gc.worktreePruneExpire controls how
       old a stale working tree should be before git worktree prune deletes
       it. Default is "3 months ago".

NOTES         top

       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, refs saved
       by git filter-branch in refs/original/, or reflogs (which may
       reference commits in branches that were later amended or rewound). 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:

        1. Any object with modification time newer than the --prune date is
           kept, along with everything reachable from it.

        2. 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) unless they turn off
       automatic garbage collection with git config 0.

HOOKS         top

       The git gc --auto command will run the pre-auto-gc hook. See
       githooks(5) for more information.

SEE ALSO         top

       git-prune(1) git-reflog(1) git-repack(1) git-rerere(1)

GIT         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control system)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual page,
       see ⟨⟩.  This page was obtained from the
       project's upstream Git repository ⟨⟩ on
       2018-10-29.  (At that time, the date of the most recent commit that
       was found in the repository was 2018-10-26.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

Git           10/28/2018                        GIT-GC(1)

Pages that refer to this page: git(1)git-clone(1)git-config(1)git-fetch(1)git-p4(1)git-pack-objects(1)git-prune(1)git-reflog(1)git-repack(1)githooks(5)gitrepository-layout(5)gitnamespaces(7)