Documentation / git-gc.txton commit Documentation: describe 'union' low-level merge driver (0e545f7)
   1git-gc(1)
   2=========
   3
   4NAME
   5----
   6git-gc - Cleanup unnecessary files and optimize the local repository
   7
   8
   9SYNOPSIS
  10--------
  11'git-gc' [--prune] [--aggressive] [--auto]
  12
  13DESCRIPTION
  14-----------
  15Runs a number of housekeeping tasks within the current repository,
  16such as compressing file revisions (to reduce disk space and increase
  17performance) and removing unreachable objects which may have been
  18created from prior invocations of gitlink:git-add[1].
  19
  20Users are encouraged to run this task on a regular basis within
  21each repository to maintain good disk space utilization and good
  22operating performance. Some git commands may automatically run
  23`git-gc`; see the `--auto` flag below for details.
  24
  25OPTIONS
  26-------
  27
  28--prune::
  29        Usually `git-gc` packs refs, expires old reflog entries,
  30        packs loose objects,
  31        and removes old 'rerere' records.  Removal
  32        of unreferenced loose objects is an unsafe operation
  33        while other git operations are in progress, so it is not
  34        done by default.  Pass this option if you want it, and only
  35        when you know nobody else is creating new objects in the
  36        repository at the same time (e.g. never use this option
  37        in a cron script).
  38
  39--aggressive::
  40        Usually 'git-gc' runs very quickly while providing good disk
  41        space utilization and performance.  This option will cause
  42        git-gc to more aggressively optimize the repository at the expense
  43        of taking much more time.  The effects of this optimization are
  44        persistent, so this option only needs to be used occasionally; every
  45        few hundred changesets or so.
  46
  47--auto::
  48        With this option, `git gc` checks whether any housekeeping is
  49        required; if not, it exits without performing any work.
  50        Some git commands run `git gc --auto` after performing
  51        operations that could create many loose objects.
  52+
  53Housekeeping is required if there are too many loose objects or
  54too many packs in the repository. If the number of loose objects
  55exceeds the value of the `gc.auto` configuration variable, then
  56all loose objects are combined into a single pack using
  57`git-repack -d -l`.  Setting the value of `gc.auto` to 0
  58disables automatic packing of loose objects.
  59+
  60If the number of packs exceeds the value of `gc.autopacklimit`,
  61then existing packs (except those marked with a `.keep` file)
  62are consolidated into a single pack by using the `-A` option of
  63`git-repack`. Setting `gc.autopacklimit` to 0 disables
  64automatic consolidation of packs.
  65
  66Configuration
  67-------------
  68
  69The optional configuration variable 'gc.reflogExpire' can be
  70set to indicate how long historical entries within each branch's
  71reflog should remain available in this repository.  The setting is
  72expressed as a length of time, for example '90 days' or '3 months'.
  73It defaults to '90 days'.
  74
  75The optional configuration variable 'gc.reflogExpireUnreachable'
  76can be set to indicate how long historical reflog entries which
  77are not part of the current branch should remain available in
  78this repository.  These types of entries are generally created as
  79a result of using `git commit \--amend` or `git rebase` and are the
  80commits prior to the amend or rebase occurring.  Since these changes
  81are not part of the current project most users will want to expire
  82them sooner.  This option defaults to '30 days'.
  83
  84The optional configuration variable 'gc.rerereresolved' indicates
  85how long records of conflicted merge you resolved earlier are
  86kept.  This defaults to 60 days.
  87
  88The optional configuration variable 'gc.rerereunresolved' indicates
  89how long records of conflicted merge you have not resolved are
  90kept.  This defaults to 15 days.
  91
  92The optional configuration variable 'gc.packrefs' determines if
  93`git gc` runs `git-pack-refs`.  Without the configuration, `git-pack-refs`
  94is not run in bare repositories by default, to allow older dumb-transport
  95clients fetch from the repository,  but this will change in the future.
  96
  97The optional configuration variable 'gc.aggressiveWindow' controls how
  98much time is spent optimizing the delta compression of the objects in
  99the repository when the --aggressive option is specified.  The larger
 100the value, the more time is spent optimizing the delta compression.  See
 101the documentation for the --window' option in gitlink:git-repack[1] for
 102more details.  This defaults to 10.
 103
 104See Also
 105--------
 106gitlink:git-prune[1]
 107gitlink:git-reflog[1]
 108gitlink:git-repack[1]
 109gitlink:git-rerere[1]
 110
 111Author
 112------
 113Written by Shawn O. Pearce <spearce@spearce.org>
 114
 115GIT
 116---
 117Part of the gitlink:git[7] suite