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GIT-MAINTENANCE(1)                           Git Manual                           GIT-MAINTENANCE(1)



NAME
       git-maintenance - Run tasks to optimize Git repository data

SYNOPSIS
       git maintenance run [<options>]


DESCRIPTION
       Run tasks to optimize Git repository data, speeding up other Git commands and reducing
       storage requirements for the repository.

       Git commands that add repository data, such as git add or git fetch, are optimized for a
       responsive user experience. These commands do not take time to optimize the Git data, since
       such optimizations scale with the full size of the repository while these user commands each
       perform a relatively small action.

       The git maintenance command provides flexibility for how to optimize the Git repository.

SUBCOMMANDS
       register
           Initialize Git config values so any scheduled maintenance will start running on this
           repository. This adds the repository to the maintenance.repo config variable in the
           current user’s global config and enables some recommended configuration values for
           maintenance.<task>.schedule. The tasks that are enabled are safe for running in the
           background without disrupting foreground processes.

           The register subcommand will also set the maintenance.strategy config value to
           incremental, if this value is not previously set. The incremental strategy uses the
           following schedule for each maintenance task:

           •   gc: disabled.

           •   commit-graph: hourly.

           •   prefetch: hourly.

           •   loose-objects: daily.

           •   incremental-repack: daily.

           git maintenance register will also disable foreground maintenance by setting
           maintenance.auto = false in the current repository. This config setting will remain after
           a git maintenance unregister command.

       run
           Run one or more maintenance tasks. If one or more --task options are specified, then
           those tasks are run in that order. Otherwise, the tasks are determined by which
           maintenance.<task>.enabled config options are true. By default, only
           maintenance.gc.enabled is true.

       start
           Start running maintenance on the current repository. This performs the same config
           updates as the register subcommand, then updates the background scheduler to run git
           maintenance run --scheduled on an hourly basis.

       stop
           Halt the background maintenance schedule. The current repository is not removed from the
           list of maintained repositories, in case the background maintenance is restarted later.

       unregister
           Remove the current repository from background maintenance. This only removes the
           repository from the configured list. It does not stop the background maintenance
           processes from running.

TASKS
       commit-graph
           The commit-graph job updates the commit-graph files incrementally, then verifies that the
           written data is correct. The incremental write is safe to run alongside concurrent Git
           processes since it will not expire .graph files that were in the previous
           commit-graph-chain file. They will be deleted by a later run based on the expiration
           delay.

       prefetch
           The prefetch task updates the object directory with the latest objects from all
           registered remotes. For each remote, a git fetch command is run. The configured refspec
           is modified to place all requested refs within refs/prefetch/. Also, tags are not
           updated.

           This is done to avoid disrupting the remote-tracking branches. The end users expect these
           refs to stay unmoved unless they initiate a fetch. With prefetch task, however, the
           objects necessary to complete a later real fetch would already be obtained, so the real
           fetch would go faster. In the ideal case, it will just become an update to a bunch of
           remote-tracking branches without any object transfer.

       gc
           Clean up unnecessary files and optimize the local repository. "GC" stands for "garbage
           collection," but this task performs many smaller tasks. This task can be expensive for
           large repositories, as it repacks all Git objects into a single pack-file. It can also be
           disruptive in some situations, as it deletes stale data. See git-gc(1) for more details
           on garbage collection in Git.

       loose-objects
           The loose-objects job cleans up loose objects and places them into pack-files. In order
           to prevent race conditions with concurrent Git commands, it follows a two-step process.
           First, it deletes any loose objects that already exist in a pack-file; concurrent Git
           processes will examine the pack-file for the object data instead of the loose object.
           Second, it creates a new pack-file (starting with "loose-") containing a batch of loose
           objects. The batch size is limited to 50 thousand objects to prevent the job from taking
           too long on a repository with many loose objects. The gc task writes unreachable objects
           as loose objects to be cleaned up by a later step only if they are not re-added to a
           pack-file; for this reason it is not advisable to enable both the loose-objects and gc
           tasks at the same time.

       incremental-repack
           The incremental-repack job repacks the object directory using the multi-pack-index
           feature. In order to prevent race conditions with concurrent Git commands, it follows a
           two-step process. First, it calls git multi-pack-index expire to delete pack-files
           unreferenced by the multi-pack-index file. Second, it calls git multi-pack-index repack
           to select several small pack-files and repack them into a bigger one, and then update the
           multi-pack-index entries that refer to the small pack-files to refer to the new
           pack-file. This prepares those small pack-files for deletion upon the next run of git
           multi-pack-index expire. The selection of the small pack-files is such that the expected
           size of the big pack-file is at least the batch size; see the --batch-size option for the
           repack subcommand in git-multi-pack-index(1). The default batch-size is zero, which is a
           special case that attempts to repack all pack-files into a single pack-file.

       pack-refs
           The pack-refs task collects the loose reference files and collects them into a single
           file. This speeds up operations that need to iterate across many references. See git-
           pack-refs(1) for more information.

OPTIONS
       --auto
           When combined with the run subcommand, run maintenance tasks only if certain thresholds
           are met. For example, the gc task runs when the number of loose objects exceeds the
           number stored in the gc.auto config setting, or when the number of pack-files exceeds the
           gc.autoPackLimit config setting. Not compatible with the --schedule option.

       --schedule
           When combined with the run subcommand, run maintenance tasks only if certain time
           conditions are met, as specified by the maintenance.<task>.schedule config value for each
           <task>. This config value specifies a number of seconds since the last time that task
           ran, according to the maintenance.<task>.lastRun config value. The tasks that are tested
           are those provided by the --task=<task> option(s) or those with
           maintenance.<task>.enabled set to true.

       --quiet
           Do not report progress or other information over stderr.

       --task=<task>
           If this option is specified one or more times, then only run the specified tasks in the
           specified order. If no --task=<task> arguments are specified, then only the tasks with
           maintenance.<task>.enabled configured as true are considered. See the TASKS section for
           the list of accepted <task> values.

       --scheduler=auto|crontab|systemd-timer|launchctl|schtasks
           When combined with the start subcommand, specify the scheduler for running the hourly,
           daily and weekly executions of git maintenance run. Possible values for <scheduler> are
           auto, crontab (POSIX), systemd-timer (Linux), launchctl (macOS), and schtasks (Windows).
           When auto is specified, the appropriate platform-specific scheduler is used; on Linux,
           systemd-timer is used if available, otherwise crontab. Default is auto.

TROUBLESHOOTING
       The git maintenance command is designed to simplify the repository maintenance patterns while
       minimizing user wait time during Git commands. A variety of configuration options are
       available to allow customizing this process. The default maintenance options focus on
       operations that complete quickly, even on large repositories.

       Users may find some cases where scheduled maintenance tasks do not run as frequently as
       intended. Each git maintenance run command takes a lock on the repository’s object database,
       and this prevents other concurrent git maintenance run commands from running on the same
       repository. Without this safeguard, competing processes could leave the repository in an
       unpredictable state.

       The background maintenance schedule runs git maintenance run processes on an hourly basis.
       Each run executes the "hourly" tasks. At midnight, that process also executes the "daily"
       tasks. At midnight on the first day of the week, that process also executes the "weekly"
       tasks. A single process iterates over each registered repository, performing the scheduled
       tasks for that frequency. Depending on the number of registered repositories and their sizes,
       this process may take longer than an hour. In this case, multiple git maintenance run
       commands may run on the same repository at the same time, colliding on the object database
       lock. This results in one of the two tasks not running.

       If you find that some maintenance windows are taking longer than one hour to complete, then
       consider reducing the complexity of your maintenance tasks. For example, the gc task is much
       slower than the incremental-repack task. However, this comes at a cost of a slightly larger
       object database. Consider moving more expensive tasks to be run less frequently.

       Expert users may consider scheduling their own maintenance tasks using a different schedule
       than is available through git maintenance start and Git configuration options. These users
       should be aware of the object database lock and how concurrent git maintenance run commands
       behave. Further, the git gc command should not be combined with git maintenance run commands.
       git gc modifies the object database but does not take the lock in the same way as git
       maintenance run. If possible, use git maintenance run --task=gc instead of git gc.

       The following sections describe the mechanisms put in place to run background maintenance by
       git maintenance start and how to customize them.

BACKGROUND MAINTENANCE ON POSIX SYSTEMS
       The standard mechanism for scheduling background tasks on POSIX systems is cron(8). This tool
       executes commands based on a given schedule. The current list of user-scheduled tasks can be
       found by running crontab -l. The schedule written by git maintenance start is similar to
       this:

           # BEGIN GIT MAINTENANCE SCHEDULE
           # The following schedule was created by Git
           # Any edits made in this region might be
           # replaced in the future by a Git command.

           0 1-23 * * * "/<path>/git" --exec-path="/<path>" for-each-repo --config=maintenance.repo maintenance run --schedule=hourly
           0 0 * * 1-6 "/<path>/git" --exec-path="/<path>" for-each-repo --config=maintenance.repo maintenance run --schedule=daily
           0 0 * * 0 "/<path>/git" --exec-path="/<path>" for-each-repo --config=maintenance.repo maintenance run --schedule=weekly

           # END GIT MAINTENANCE SCHEDULE


       The comments are used as a region to mark the schedule as written by Git. Any modifications
       within this region will be completely deleted by git maintenance stop or overwritten by git
       maintenance start.

       The crontab entry specifies the full path of the git executable to ensure that the executed
       git command is the same one with which git maintenance start was issued independent of PATH.
       If the same user runs git maintenance start with multiple Git executables, then only the
       latest executable is used.

       These commands use git for-each-repo --config=maintenance.repo to run git maintenance run
       --schedule=<frequency> on each repository listed in the multi-valued maintenance.repo config
       option. These are typically loaded from the user-specific global config. The git maintenance
       process then determines which maintenance tasks are configured to run on each repository with
       each <frequency> using the maintenance.<task>.schedule config options. These values are
       loaded from the global or repository config values.

       If the config values are insufficient to achieve your desired background maintenance
       schedule, then you can create your own schedule. If you run crontab -e, then an editor will
       load with your user-specific cron schedule. In that editor, you can add your own schedule
       lines. You could start by adapting the default schedule listed earlier, or you could read the
       crontab(5) documentation for advanced scheduling techniques. Please do use the full path and
       --exec-path techniques from the default schedule to ensure you are executing the correct
       binaries in your schedule.

BACKGROUND MAINTENANCE ON LINUX SYSTEMD SYSTEMS
       While Linux supports cron, depending on the distribution, cron may be an optional package not
       necessarily installed. On modern Linux distributions, systemd timers are superseding it.

       If user systemd timers are available, they will be used as a replacement of cron.

       In this case, git maintenance start will create user systemd timer units and start the
       timers. The current list of user-scheduled tasks can be found by running systemctl --user
       list-timers. The timers written by git maintenance start are similar to this:

           $ systemctl --user list-timers
           NEXT                         LEFT          LAST                         PASSED     UNIT                         ACTIVATES
           Thu 2021-04-29 19:00:00 CEST 42min left    Thu 2021-04-29 18:00:11 CEST 17min ago  git-maintenance AT hourly.timer git-maintenance AT hourly.service
           Fri 2021-04-30 00:00:00 CEST 5h 42min left Thu 2021-04-29 00:00:11 CEST 18h ago    git-maintenance AT daily.timer  git-maintenance AT daily.service
           Mon 2021-05-03 00:00:00 CEST 3 days left   Mon 2021-04-26 00:00:11 CEST 3 days ago git-maintenance AT weekly.timer git-maintenance AT weekly.service


       One timer is registered for each --schedule=<frequency> option.

       The definition of the systemd units can be inspected in the following files:

           ~/.config/systemd/user/git-maintenance@.timer
           ~/.config/systemd/user/git-maintenance@.service
           ~/.config/systemd/user/timers.target.wants/git-maintenance AT hourly.timer
           ~/.config/systemd/user/timers.target.wants/git-maintenance AT daily.timer
           ~/.config/systemd/user/timers.target.wants/git-maintenance AT weekly.timer


       git maintenance start will overwrite these files and start the timer again with systemctl
       --user, so any customization should be done by creating a drop-in file, i.e. a .conf suffixed
       file in the ~/.config/systemd/user/git-maintenance@.service.d directory.

       git maintenance stop will stop the user systemd timers and delete the above mentioned files.

       For more details, see systemd.timer(5).

BACKGROUND MAINTENANCE ON MACOS SYSTEMS
       While macOS technically supports cron, using crontab -e requires elevated privileges and the
       executed process does not have a full user context. Without a full user context, Git and its
       credential helpers cannot access stored credentials, so some maintenance tasks are not
       functional.

       Instead, git maintenance start interacts with the launchctl tool, which is the recommended
       way to schedule timed jobs in macOS. Scheduling maintenance through git maintenance
       (start|stop) requires some launchctl features available only in macOS 10.11 or later.

       Your user-specific scheduled tasks are stored as XML-formatted .plist files in
       ~/Library/LaunchAgents/. You can see the currently-registered tasks using the following
       command:

           $ ls ~/Library/LaunchAgents/org.git-scm.git*
           org.git-scm.git.daily.plist
           org.git-scm.git.hourly.plist
           org.git-scm.git.weekly.plist


       One task is registered for each --schedule=<frequency> option. To inspect how the XML format
       describes each schedule, open one of these .plist files in an editor and inspect the <array>
       element following the <key>StartCalendarInterval</key> element.

       git maintenance start will overwrite these files and register the tasks again with launchctl,
       so any customizations should be done by creating your own .plist files with distinct names.
       Similarly, the git maintenance stop command will unregister the tasks with launchctl and
       delete the .plist files.

       To create more advanced customizations to your background tasks, see launchctl.plist(5) for
       more information.

BACKGROUND MAINTENANCE ON WINDOWS SYSTEMS
       Windows does not support cron and instead has its own system for scheduling background tasks.
       The git maintenance start command uses the schtasks command to submit tasks to this system.
       You can inspect all background tasks using the Task Scheduler application. The tasks added by
       Git have names of the form Git Maintenance (<frequency>). The Task Scheduler GUI has ways to
       inspect these tasks, but you can also export the tasks to XML files and view the details
       there.

       Note that since Git is a console application, these background tasks create a console window
       visible to the current user. This can be changed manually by selecting the "Run whether user
       is logged in or not" option in Task Scheduler. This change requires a password input, which
       is why git maintenance start does not select it by default.

       If you want to customize the background tasks, please rename the tasks so future calls to git
       maintenance (start|stop) do not overwrite your custom tasks.

GIT
       Part of the git(1) suite



Git 2.34.1                                   02/26/2026                           GIT-MAINTENANCE(1)