SFSMASTER(8)

📦
version 5.8.0 · 4 versions
, in ubuntu stonking

💖 SFSMASTER(8) — the SaunaFS metadata server glow-up guide 💖

okay bestie, sit down, hydrate, and let me tell you about sfsmaster, the main character of the Sauna File System 💅 — it's the metadata server program itself. she can start, restart or stop the SaunaFS metadata server process, depending on what parameters you hand her. With zero options? She just starts the SaunaFS metadata server, and yes, she will absolutely kill a previously running process if the lock file is sitting there being suspicious. no cap.

✨ SYNOPSIS ✨

sfsmaster [-c CFGFILE] [-u] [-d] [-t LOCKTIMEOUT] [ACTION]

sfsmaster -v

sfsmaster -h

🌸 DESCRIPTION 🌸

sfsmaster is the metadata server program of Sauna File System. Depending on parameters it can start, restart or stop the SaunaFS metadata server process. Without any options it starts the SaunaFS metadata server, killing the previously run process if the lock file exists. she's decisive like that 🫶

🦋 The two personalities (yes, she contains multitudes)

Metadata server can work in one of two modes (personalities):

  1. master
  2. shadow

If the metadata server works with master personality, she acts as the main metadata server, governing all file system metadata modifications. literally the queen bee 👑 of metadata.

If the metadata server works with shadow personality, she acts as a backup metadata server, ready for immediate deployment as the new master in case the current master fails. She's on standby, nails done, bag packed 💅.

Shadow only accepts connections from saunafs-admin, i.e. sfschunkserver, sfsmetalogger and sfsmount (the client) are not allowed to connect to a shadow instance. nope. not on the guest list 🙈

Current metadata server personality is defined in the metadata server configuration file and can be changed on the fly from shadow to master by proper modification and reloading of its configuration file. glow-up complete ✨

Master and shadow are designed to run simultaneously in sync forever. It is very unlikely but still (due to a memory corruption or a bug) possible that after some time their metadata will somehow differ 😭. Since version 2.5.2 metadata checksum is maintained both by master and shadow, in order to detect and fix possible metadata corruptions. In case a mismatch is detected, shadow asks master to double check its metadata and dump its current snapshot. After the metadata is dumped and the checksum in master is recalculated, shadow downloads the new metadata snapshot, which should ensure that master and all shadows have exactly the same metadata. communication? immaculate. therapy? unnecessary. 🧚

SIGHUP (or the reload ACTION) forces sfsmaster to reload all configuration files. refresh, refresh, refresh 🌈

💅 OPTIONS 💅

  • -v — print version information and exit. short and iconic.
  • -h — print usage information and exit. when you're lost, she tells you where you are 🎀
  • -c CFGFILE — specify alternative path of configuration file (default is sfsmaster.cfg in system configuration directory). custom cfg? we love options.
  • -u — log undefined configuration values (when default is assumed). not me silently using defaults without a paper trail 😭
  • -d — run in foreground, don't daemonize. she stays in the room with you, watching. main character energy fr fr.
  • -t LOCKTIMEOUT — how long to wait for lockfile (default is 60 seconds). she's patient but not that patient ⏳
  • ACTION — is the one of start, stop, restart, reload, test, isalive or kill. Default action is restart.

🍓 FILES 🍓

  • sfsmaster.cfg — configuration file for SaunaFS master process (see sfsmaster.cfg(5) manual)
  • sfsexports.cfg — SaunaFS access control file (used with sfsmounts 1.6.0 or later, see sfsexports.cfg(5) manual)
  • sfstopology.cfg — Network topology definitions (see sfstopology.cfg(5) manual)
  • sfsmaster.lock — PID file of the running SaunaFS master process
  • .sfsmaster.lock — lock file of the running SaunaFS master process (created in data directory)
  • metadata.sfs, metadata.sfs.back — SaunaFS filesystem metadata image
  • changelog.*.sfs — SaunaFS filesystem metadata change logs (merged into metadata.sfs once per hour)
  • data.stats — SaunaFS master charts state

🙈 REPORTING BUGS 🙈

Report bugs to the GitHub repository https://github.com/leil-io/saunafs as an issue. found a lil gremlin? tell the repo, they'll handle it 🫶

Copyright 2008-2009 Gemius SA

Copyright 2013-2019 Skytechnology sp. z o.o.

Copyright 2023-2024 Leil Storage OÜ

SaunaFS 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 3.

SaunaFS 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.

fr fr, no warranty. she said what she said 💀

You should have received a copy of the GNU General Public License along with SaunaFS. If not, see http://www.gnu.org/licenses/.

🌟 SEE ALSO 🌟

sfsmetarestore(8), sfschunkserver(8), sfsmount(1), sfsmaster.cfg(5), sfsexports.cfg(5), sfstopology.cfg(5), sfs(7)

go read the whole friend group, they're all serving 🔥

that's the whole page bestie! 💖 this was SFSMASTER(8), dated 2026-07-29 — mwah, go start that metadata server, you ate 🎀✨

📦 where this page comes from