mfsmaster(8)

📦
version 4.59.2 · 6 versions
, in arch rolling, nixos 26.05, nixpkgs unstable, ubuntu stonking

💖 mfsmaster(8) 💖

okay bestie, pull up a chair, because we're talking about mfsmaster — that's the MooseFS master program, the literal main character of your whole filesystem, and yes she comes with her very own manual page (this one, mfsmaster(8), girlboss edition). 🎀

✨ NAME ✨

mfsmaster — start, restart or stop MooseFS master process

no cap, that's the whole job description and she ate 💅

🌸 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. that's it, that's the description the original gave us, and honestly she's iconic for saying so little 👑

💜 OPTIONS 💜

  • -v — print version information and exit. short queen energy, in and out, no notes ✨
  • -h — print usage information and exit. when you're lost, she'll hold your hand 🫶
  • -c CFGFILE — specify an alternative path for the configuration file (the default is mfsmaster.cfg in the system configuration directory). custom config era 💅
  • -f — run in foreground, don't daemonize. she stays in the room with you, watching, respectfully 👀
  • -d — run with dangerous options (names: DANGEROUS_*). as the name fr fr says: dangerous. proceed with the awareness of someone who read the label 🌈
  • -u — log undefined configuration values (when the default is assumed). she's telling on your config file, kindly 💖
  • -n — do not attempt to increase the limit of core dump size. minding her own business about your core dumps 🎀
  • -i — ignore some metadata structure errors. bold. risky. lowkey a choice, but she said trust me ✨
  • -a — automatically restore metadata from change logs. healing arc 🦋
  • -e — (pro only) start without metadata (used to start additional masters). pro girlies only 💅
  • -x — produce more verbose output. she starts talking more 🗣️
  • -xx — even more verbose output. and then she starts talking even more 😭
  • -t LOCKTIMEOUT — how long to wait for the lockfile, in seconds (the default is 1800 seconds). that's a whole 30 minutes of patiently waiting for that lock, bestie ⏳

🎀 ACTION 🎀

ACTION tells the master to perform one of the following actions. pick your fighter:

  • start — start the master process if the process is not already running, otherwise display an error message. she's not doing double shifts 💅
  • stop — stop the master process if the process is running, otherwise display an error message. rest era, she earned it 😴
  • restart — (this is the default action) if the master process is running, restart it; if it's not running, start it. glow-up either way ✨
  • reload — send a signal to the master process to reload config files. fresh config, same queen 🦋
  • info — send a signal to the master process to dump a debug information file in the working directory. receipts, kept 📄
  • test — displays "mfsmaster pid: PID" if the master is running (and returns 0), or "mfsmaster is not running" otherwise (and returns 1). vibe check with an actual exit status 🔥
  • kill — send a termination signal to the master process. dramatic exit, we don't blame her 💀
  • restore — restore the current metadata file using the backup metadata and changelog files (if possible, i.e. if the correct files exist), write it to the working directory and exit. resurrection arc, and it only works if the files are actually there 🙈

🌈 FILES 🌈

everything below lives in her world. the data-directory girlies are flagged, iykyk 💖

  • mfsmaster.cfg — configuration file for the MooseFS master process; refer to the mfsmaster.cfg(5) manual for details
  • mfsexports.cfg — MooseFS access control file; refer to the mfsexports.cfg(5) manual for details
  • mfstopology.cfg — network topology definitions; refer to the mfstopology.cfg(5) manual for details
  • mfsipmap.cfg — chunkservers IP mapping definitions; refer to the mfsipmap.cfg(5) manual for details
  • .mfsmaster.lock — lock file of the running MooseFS master process (created in the data directory)
  • .bgwriter.lock — lock file of the running MooseFS master subprocess for storing metadata (created in the data directory)
  • metadata.mfs, metadata.mfs.back — MooseFS filesystem metadata image (created in the data directory)
  • metadata.crc — CRC of the metadata.mfs file (created in the data directory)
  • metadata.mfs.empty — an empty metadata file, to be used when starting up a fresh MooseFS instance (created in the data directory)
  • changelog.*.mfs — MooseFS filesystem metadata change logs (created in the data directory)
  • stats.mfs — master charts stats (created in the 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 the data directory)

😭 REPORTING BUGS 😭

report bugs to <bugs@moosefs.com>. she wants to hear about it, fr fr, don't be shy 🫶

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), mfsmount(8), mfsmaster.cfg(5), mfsexports.cfg(5), mfstopology.cfg(5)

and that's the whole thing, bestie 💖 this was MooseFS 4.59.2-1, dated May 2026, and she slayed every second of it. go forth, run your master, and remember — you're doing amazing, periodt ✨👑🦋

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