---
name: "mfsmaster"
section: "8"
platform: "linux"
package: "moosefs"
version: "4.59.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/mfsmaster"
---

# mfsmaster(8)

start, restart or stop MooseFS master process

## NAME

mfsmaster - start, restart or stop MooseFS master process

## SYNOPSIS

**mfsmaster** \[**-c** *CFGFILE*\] \[**-f**\] \[**-d**\] \[**-u**\] \[**-n**\] \[**-i**\] \[**-a**\] \[**-e**\] \[**-x**\[**x**\]\] \[**-t** *LOCKTIMEOUT*\] \[*ACTION*\]

**mfsmaster -v**

**mfsmaster -h**

## DESCRIPTION

**mfsmaster** is the master program of MooseFS.

## OPTIONS

- **-v**

  print version information and exit

- **-h**

  print usage information and exit

- **-c** *CFGFILE*

  specify alternative path of configuration file (default is **mfsmaster.cfg** in system configuration directory)

- **-f**

  run in foreground, don't daemonize

- **-d**

  run with dangerous options (names: DANGEROUS\_\*)

- **-u**

  log undefined configuration values (when default is assumed)

- **-n**

  do not attempt to increase limit of core dump size

- **-i**

  ignore some metadata structure errors

- **-a**

  automatically restore metadata from change logs

- **-e**

  (pro only) start without metadata (used to start additional masters)

- **-x**

  produce more verbose output

- **-xx**

  even more verbose output

- **-t** *LOCKTIMEOUT*

  how long to wait for lockfile (in seconds; default is 1800 seconds)

- *ACTION*

  tells master to perform one of the following actions:

  - start

    Start master process if the process is not already running, otherwise display error message.

  - stop

    Stop master process if the process is running, otherwise display error message.

  - restart

    (default action) If the master process is running, restart it, if it's not running, start it.

  - reload

    Send a signal to master process to reload config files.

  - info

    Send a signal to master process to dump debug information file in working directory.

  - test

    Displays "mfsmaster pid: PID" if the master is running (and return 0) or  "mfsmaster is not running" otherwise (and return 1).

  - kill

    Send termination signal to master process.

  - restore

    Restore current metadata file using backup metadata and changelog files (if possible, i.e. if correct files exist), write it to working directory and exit.

## FILES

- **mfsmaster.cfg**

  configuration file for MooseFS master process; refer to [**mfsmaster.cfg**(5)](/mfsmaster.cfg/5.md) manual for details

- **mfsexports.cfg**

  MooseFS access control file; refer to [**mfsexports.cfg**(5)](/mfsexports.cfg/5.md) manual for details

- **mfstopology.cfg**

  Network topology definitions; refer to [**mfstopology.cfg**(5)](/mfstopology.cfg/5.md) manual for details

- **mfsipmap.cfg**

  Chunkservers IP mapping definitions; refer to [**mfsipmap.cfg**(5)](/mfsipmap.cfg/5.md) manual for details

- **.mfsmaster.lock**

  lock file of running MooseFS master process (created in data directory)

- **.bgwriter.lock**

  lock file of running MooseFS master subprocess for storing metadata (created in data directory)

- **metadata.mfs**, **metadata.mfs.back**

  MooseFS filesystem metadata image (created in data directory)

- **metadata.crc**

  CRC of **metadata.mfs** file (created in data directory)

- **metadata.mfs.empty**

  An empty metadata file, to be used when starting up a fresh MooseFS instance (created in data directory)

- **changelog.**\***.mfs**

  MooseFS filesystem metadata change logs (created in data directory)

- **stats.mfs**

  master charts stats (created in data directory)

- **.mfsmaster\_info.txt**

  master info file, created by sending the process INFO signal, with work parameters that can be used for debugging/support purposes (created in data directory)

## REPORTING BUGS

Report bugs to \<bugs@moosefs.com\>.

## COPYRIGHT

Copyright (C) 2026 Jakub Kruszona-Zawadzki, Saglabs SA

This file is part of MooseFS.

MooseFS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2 (only).

MooseFS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, see \<https://www.gnu.org/licenses/\>.

## SEE ALSO

[**mfschunkserver**(8)](/mfschunkserver/8.md), [**mfsmount**(8)](/mfsmount/8.md), [**mfsmaster.cfg**(5)](/mfsmaster.cfg/5.md), [**mfsexports.cfg**(5)](/mfsexports.cfg/5.md), [**mfstopology.cfg**(5)](/mfstopology.cfg/5.md)