GIT-FSMONITOR--DAEMON(1)

NAME
git-fsmonitor--daemon - A Built-in Filesystem Monitor

SYNOPSIS

git fsmonitor--daemon start
git fsmonitor--daemon run
git fsmonitor--daemon stop
git fsmonitor--daemon status

DESCRIPTION

A daemon to watch the working directory for file and directory changes using platform-specific filesystem notification facilities.

This daemon communicates directly with commands like git status using the simple IPC[1] interface instead of the slower githooks(5) interface.

This daemon is built into Git so that no third-party tools are required.

OPTIONS

start
    Starts a daemon in the background.

run
    Runs a daemon in the foreground.

stop
    Stops the daemon running in the current working directory, if present.

status
    Exits with zero status if a daemon is watching the current working directory.

REMARKS

This daemon is a long running process used to watch a single working directory and maintain a list of the recently changed files and directories. Performance of commands such as git status can be increased if they just ask for a summary of changes to the working directory and can avoid scanning the disk.

When core.fsmonitor is set to true (see git-config(1)) commands, such as git status, will ask the daemon for changes and automatically start it (if necessary).

For more information see the "File System Monitor" section in git-update-index(1).

CAVEATS

The fsmonitor daemon does not currently know about submodules and does not know to filter out filesystem events that happen within a submodule. If fsmonitor daemon is watching a super repo and a file is modified within the working directory of a submodule, it will report the change (as happening against the super repo). However, the client will properly ignore these extra events, so performance may be affected but it will not cause an incorrect result.

By default, the fsmonitor daemon refuses to work with network-mounted repositories; this may be overridden by setting fsmonitor.allowRemote to true. Note, however, that the fsmonitor daemon is not guaranteed to work correctly with all network-mounted repositories, so such use is considered experimental.

On Mac OS and Linux, the inter-process communication (IPC) between various Git commands and the fsmonitor daemon is done via a Unix domain socket (UDS) — a special type of file — which is supported by native Mac OS and Linux filesystems, but not on network-mounted filesystems, NTFS, or FAT32. Other filesystems may or may not have the needed support; the fsmonitor daemon is not guaranteed to work with these filesystems and such use is considered experimental.

By default, the socket is created in the .git directory. However, if the .git directory is on a network-mounted filesystem, it will instead be created at $HOME/.git-fsmonitor-* unless $HOME itself is on a network-mounted filesystem, in which case you must set the configuration variable fsmonitor.socketDir to the path of a directory on a native filesystem in which to create the socket file.

If none of the above directories (.git, $HOME, or fsmonitor.socketDir) is on a native filesystem the fsmonitor daemon will report an error that will cause the daemon and the currently running command to exit.

  LINUX CAVEATS

On Linux, the fsmonitor daemon uses inotify to monitor filesystem events. The inotify system has per-user limits on the number of watches that can be created. The default limit is typically 8192 watches per user.

For large repositories with many directories, you may need to increase this limit. Check the current limit with:

    cat /proc/sys/fs/inotify/max_user_watches

To temporarily increase the limit:

    sudo sysctl fs.inotify.max_user_watches=65536

To make the change permanent, add to /etc/sysctl.conf:

    fs.inotify.max_user_watches=65536

CONFIGURATION

Everything below this line in this section is selectively included from the git-config(1) documentation. The content is the same as what’s found there:

fsmonitor.allowRemote
    By default, the fsmonitor daemon refuses to work with network-mounted repositories. Setting fsmonitor.allowRemote to true overrides this behavior. Only respected when core.fsmonitor is set to true.

fsmonitor.socketDir
    This Mac OS and Linux-specific option, if set, specifies the directory in which to create the Unix domain socket used for communication between the fsmonitor daemon and various Git commands. The directory must reside on a native filesystem. Only respected when core.fsmonitor is set to true.

GIT

Part of the git(1) suite

NOTES

1.  simple IPC
    git-htmldocs/technical/api-simple-ipc.html