MFSMOUNT(1)

📦 version 3.12.0, in fedora 43

💖 MFSMOUNT(1) — the bestie guide to mfsmount 💖

okay so. this is the manual page for mfsmount, from section 1 of the manual (you know, the "user commands" section, the one you actually type). we're gonna mount the Lizard File System together and it's gonna be so slay. grab a snack. 🍓

✨ NAME ✨

mfsmount — mount Lizard File System

like. that's the whole job. it mounts the Lizard File System. iconic behavior honestly 👑

🌈 SYNOPSIS 🌈

mfsmount mountpoint [-d] [-f] [-s] [-m] [-n] [-p]
         [-H HOST] [-P PORT] [-S PATH] [-o opt[,opt]...]

mfsmount -h|--help

mfsmount -V|--version

so you give it a mountpoint, sprinkle in whatever flags you vibe with, and it does the thing. the last two forms are just "tell me stuff" mode — no mounting, just info. 🫶

🦋 DESCRIPTION 🦋

Mount Lizard File System. that's it, that's the description. short king of a sentence. 💅

General options

these are the "just tell me what's going on" options:

  • -h, --help — display help and exit. you get the lil instruction sheet and then it dips. 👋
  • -V — display version information and exit. it tells you what version you're running and then it's gone.

FUSE options

these ones come from the FUSE side of the house:

  • -d, -o debug — enable debug mode. heads up: this implies -f, so you're automatically in the foreground whether you asked or not. 🙈
  • -f — foreground operation. it stays in your terminal instead of yeeting itself into the background.
  • -s — disable multi-threaded operation. single-threaded, one thing at a time, very mindful.

LizardFS options

okay this is the big one, the main character section, the moment we've all been waiting for:

  • -c CFGFILE, -o mfscfgfile=CFGFILE — loads file with additional mount options. it reads CFGFILE and pulls extra mount options out of it.
  • -m, --meta, -o mfsmeta — mount MFSMETA companion filesystem instead of primary LizardFS. so instead of the normal one, you get the MFSMETA buddy filesystem.
  • -n — omit default mount options (-o allow_other,default_permissions). you're saying "no thank u to the defaults bestie."
  • -p, -o askpassword — prompt for password. this is literally the interactive version of -o mfspassword=PASS, so it asks you instead of you putting it in the command line like a menace.
  • -H HOST, -o mfsmaster=HOST — connect with LizardFS master on HOST. the default is mfsmaster.
  • -P PORT, -o mfsport=PORT — connect with LizardFS master on PORT. the default is 9421.
  • -B HOST, -o mfsbind=HOST — local address to use for connecting with master instead of default one. so like, which of your local addresses it goes out from.
  • -S PATH, -o mfssubfolder=PATH — mount specified LizardFS directory. the default is /, i.e. whole filesystem — the entire thing, all of it, the whole buffet.
  • -o enablefilelocks=[0,1] — enables/disables global file locking. disabled by default, so it's off unless you say otherwise.
  • -o mfspassword=PASSWORD — authenticate to LizardFS master with PASSWORD.
  • -o mfsmd5pass=MD5 — authenticate to LizardFS master using directly given MD5. note the vibe: this is only if mfspassword option is not specified.
  • -o mfsdelayedinit — connection with master is done in background. with this option mount can be run without network — which is good for being run from fstab / init scripts etc. very "i'll catch up with you later" energy. 😌
  • -o mfsacl — enable ACL support. disabled by default.
  • -o mfsaclcacheto=SEC — set ACL cache timeout in seconds. default: 1.0.
  • -o mfsaclcachesize=N — define ACL cache size in number of entries. 0 means no cache. default: 1000.
  • -o mfsrwlock=0|1 — when set to 1, parallel reads from the same descriptor are performed. default: 1.
  • -o mfsmkdircopysgid=N — sgid bit should be copied during mkdir operation. on linux default: 1, otherwise: 0.
  • -o mfssugidclearmode=SMODE — set sugid clear mode. see below (there's a whole section, don't worry, i got you 👇).
  • -o mfsdebug — print some LizardFS-specific debugging information. it gets chatty. 🗣️
  • -o mfscachemode=CACHEMODE — set cache mode. see DATA CACHE MODES. default is AUTO.
  • -o mfscachefiles — (deprecated) preserve file data in cache. it's equivalent to -o mfscachemode=YES. deprecated!! so like, use the other one. ⚠️
  • -o mfsattrcacheto=SEC — set attributes cache timeout in seconds. default: 1.0.
  • -o mfsentrycacheto=SEC — set file entry cache timeout in seconds. default: 0.0, i.e. no cache.
  • -o mfsdirentrycacheto=SEC — set directory entry cache timeout in seconds. default: 1.0.
  • -o mfswritecachesize=N — specify write cache size in MiB. in range: 16..2048. default: 128.
  • -o mfscacheperinodepercentage=N — specify what part of the write cache non occupied by other inodes can a single inode occupy (measured in %). E.g. When N=75 and the inode X uses 10 MiB, and all other inodes use 20 MiB out of 100 MiB cache, X can use 50 MiB more (since 75% of 80 MiB is 60 MiB). Default: 25. math is math bestie, it's giving ✨calculus✨
  • -o mfschunkserverreadto=MSEC — set timeout for whole communication with a chunkserver during read operation in milliseconds. default: 2000.
  • -o mfschunkserverwriteto=MSEC — set chunkserver response timeout during write operation in milliseconds. default: 5000.
  • -o mfschunkserverrtt=MSEC — set timeout after which SYN packet is considered lost during the first retry of connecting a chunkserver. default: 200.
  • -o mfschunkserverconnectreadto=MSEC — set timeout for connecting with chunkservers during read operation in milliseconds. default: 2000.
  • -o mfschunkserverwavereadto=MSEC — set timeout for executing each wave of a read operation in milliseconds. default: 500.
  • -o mfschunkservertotalreadto=MSEC — set timeout for the whole communication with chunkservers during a read operation in milliseconds. default: 2000.
  • -o cacheexpirationtime=MSEC — set timeout for read cache entries to be considered valid in milliseconds. 0 disables cache. default: 300.
  • -o readaheadmaxwindowsize=KB — set max value of readahead window per single descriptor in kibibytes. default: 16384.
  • -o mfsrlimitnofile=N — try to change limit of simultaneously opened file descriptors on startup. default: 100000.
  • -o mfsnice=LEVEL — try to change nice level to specified value on startup. default: -19.
  • -o mfswriteworkers=N — define number of write workers. default: 10.
  • -o mfswritewindowsize=N — define write window size (in blocks) for each chunk. default: 15.
  • -o mfsmemlock — try to lock memory. note: must be enabled at build time.
  • -o mfsdonotrememberpassword — do not remember password in memory. more secure, but when session is lost then new session is created without password. tradeoffs, we love a tradeoff 🫠
  • -o mfsioretries=N — specify number of retries before I/O error is returned. default: 30.
  • -o mfsreportreservedperiod=N — specify interval of reporting reserved inodes in seconds. default: 60.
  • -o mfsiolimits=PATH — specify local I/O limiting configuration file. default: no I/O limiting.

General mount options

these are the classic ones, see mount(8) manual for the full lore:

  • -o rw | -o ro — Mount file-system in read-write (default) or read-only mode respectively.
  • -o suid | -o nosuid — Enable or disable suid/sgid attributes to work.
  • -o dev | -o nodev — Enable or disable character or block special device files interpretation.
  • -o exec | -o noexec — Allow or disallow execution of binaries.
  • -o symlinkcachetimeout=N — Set timeout value for symlink cache timeout in seconds. Default value is 3600.
  • -o bandwidthoveruse=N — Define ratio of allowed bandwidth overuse when fetching data. Default value is 1.0. This option is effective only with N+M goals (xors and erasure codes).

🎀 DATA CACHE MODES 🎀

There are three cache modes: NO, YES and AUTO. Default option is AUTO and you shuldn’t change it unless you really know what you are doing. In AUTO mode data cache is managed automatically by mfsmaster.

  • NO, NONE or NEVER — never allow files data to be kept in cache. safest but can reduce efficiency. 🛡️
  • YES or ALWAYS — always allow files data to be kept in cache. dangerous. 💀
  • AUTO — file cache is managed by mfsmaster automatically. should be very safe and efficient.
so like, the vibes are: NO is the safe-but-slow one, YES is the fast-but-risky one (they literally call it dangerous, be so serious), and AUTO is the "let the master handle it" one which should be very safe and efficient. leave AUTO alone. periodt.

👑 SUGID CLEAR MODE 👑

SMODE can be set to:

  • NEVER — MFS will not change suid and sgid bit on chown
  • ALWAYS — clear suid and sgid on every chown. safest operation
  • OSX — standard behavior in OS X and Solaris (chown made by unprivileged user clear suid and sgid)
  • BSD — standard behavior in BSD systems (like in OSX, but only when something is really changed)
  • EXT — standard behavior in most file systems on Linux (directories not changed, others: suid cleared always, sgid only when group exec bit is set)
  • XFS — standard behavior in XFS on Linux (like EXT but directories are changed by unprivileged users)

SMODE extra info:

btrfs, ext2, ext3, ext4, hfs[+], jfs, ntfs and reiserfs on Linux work as EXT.

Only xfs on Linux works a little different. Beware that there is a strange operation — chown(-1,-1) — which is usually converted by a kernel into something like chmod ug-s, and therefore can’t be controlled by MFS as chown. 😭 yeah that one's a lil cursed, not gonna lie.

🙈 REPORTING BUGS 🙈

Report bugs to <contact@lizardfs.org>.

found something broken? tell the lizard people. they wanna know. fr fr. 🦎

Copyright 2008-2009 Gemius SA, 2013-2015 Skytechnology sp. z o.o.

LizardFS 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.

LizardFS 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 LizardFS. If not, see http://www.gnu.org/licenses/.

no warranty bestie!! it's free software, it's GPL v3, and if you didn't get your copy of the license, the link is right there. that's the whole legal tea. ☕

🌸 SEE ALSO 🌸

mfsmaster(8), mfstools(1), moosefs(7), mount(8)

go read those too, they're all in the same friend group. 💖

and that's the whole page!! this version was dated 07/24/2025, from the LizardFS corner of the internet — mwah, go mount something gorgeous. 💅✨🦋

📦 where this page comes from