You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

2114 lines
48 KiB

<!doctype html>
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta name="description" content="mergerfs - a featureful union filesystem">
<link rel="canonical" href="https://trapexit.github.io/mergerfs/config/options/">
<link rel="prev" href="../../intro_to_filesystems/">
<link rel="next" href="../deprecated_options/">
<link rel="icon" href="../../assets/images/favicon.png">
<meta name="generator" content="mkdocs-1.6.1, mkdocs-material-9.6.12">
<title>Options - mergerfs</title>
<link rel="stylesheet" href="../../assets/stylesheets/main.2afb09e1.min.css">
<link rel="stylesheet" href="../../assets/stylesheets/palette.06af60db.min.css">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,300i,400,400i,700,700i%7CRoboto+Mono:400,400i,700,700i&display=fallback">
<style>:root{--md-text-font:"Roboto";--md-code-font:"Roboto Mono"}</style>
<script>__md_scope=new URL("../..",location),__md_hash=e=>[...e].reduce(((e,_)=>(e<<5)-e+_.charCodeAt(0)),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script>
</head>
<body dir="ltr" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo">
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
<label class="md-overlay" for="__drawer"></label>
<div data-md-component="skip">
<a href="#options" class="md-skip">
Skip to content
</a>
</div>
<div data-md-component="announce">
</div>
<header class="md-header md-header--shadow" data-md-component="header">
<nav class="md-header__inner md-grid" aria-label="Header">
<a href="../.." title="mergerfs" class="md-header__button md-logo" aria-label="mergerfs" data-md-component="logo">
<img src="../../logo.png" alt="logo">
</a>
<label class="md-header__button md-icon" for="__drawer">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3zm0 5h18v2H3zm0 5h18v2H3z"/></svg>
</label>
<div class="md-header__title" data-md-component="header-title">
<div class="md-header__ellipsis">
<div class="md-header__topic">
<span class="md-ellipsis">
mergerfs
</span>
</div>
<div class="md-header__topic" data-md-component="header-topic">
<span class="md-ellipsis">
Options
</span>
</div>
</div>
</div>
<form class="md-header__option" data-md-component="palette">
<input class="md-option" data-md-color-media="(prefers-color-scheme)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to light mode" type="radio" name="__palette" id="__palette_0">
<label class="md-header__button md-icon" title="Switch to light mode" for="__palette_1" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m14.3 16-.7-2h-3.2l-.7 2H7.8L11 7h2l3.2 9zM20 8.69V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12zm-9.15 3.96h2.3L12 9z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: light)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to dark mode" type="radio" name="__palette" id="__palette_1">
<label class="md-header__button md-icon" title="Switch to dark mode" for="__palette_2" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a4 4 0 0 0-4 4 4 4 0 0 0 4 4 4 4 0 0 0 4-4 4 4 0 0 0-4-4m0 10a6 6 0 0 1-6-6 6 6 0 0 1 6-6 6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: dark)" data-md-color-scheme="slate" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to system preference" type="radio" name="__palette" id="__palette_2">
<label class="md-header__button md-icon" title="Switch to system preference" for="__palette_0" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 18c-.89 0-1.74-.2-2.5-.55C11.56 16.5 13 14.42 13 12s-1.44-4.5-3.5-5.45C10.26 6.2 11.11 6 12 6a6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12z"/></svg>
</label>
</form>
<script>var palette=__md_get("__palette");if(palette&&palette.color){if("(prefers-color-scheme)"===palette.color.media){var media=matchMedia("(prefers-color-scheme: light)"),input=document.querySelector(media.matches?"[data-md-color-media='(prefers-color-scheme: light)']":"[data-md-color-media='(prefers-color-scheme: dark)']");palette.color.media=input.getAttribute("data-md-color-media"),palette.color.scheme=input.getAttribute("data-md-color-scheme"),palette.color.primary=input.getAttribute("data-md-color-primary"),palette.color.accent=input.getAttribute("data-md-color-accent")}for(var[key,value]of Object.entries(palette.color))document.body.setAttribute("data-md-color-"+key,value)}</script>
<label class="md-header__button md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.52 6.52 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5"/></svg>
</label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="__search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" required>
<label class="md-search__icon md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.52 6.52 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5"/></svg>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11z"/></svg>
</label>
<nav class="md-search__options" aria-label="Search">
<a href="javascript:void(0)" class="md-search__icon md-icon" title="Share" aria-label="Share" data-clipboard data-clipboard-text="" data-md-component="search-share" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M18 16.08c-.76 0-1.44.3-1.96.77L8.91 12.7c.05-.23.09-.46.09-.7s-.04-.47-.09-.7l7.05-4.11c.54.5 1.25.81 2.04.81a3 3 0 0 0 3-3 3 3 0 0 0-3-3 3 3 0 0 0-3 3c0 .24.04.47.09.7L8.04 9.81C7.5 9.31 6.79 9 6 9a3 3 0 0 0-3 3 3 3 0 0 0 3 3c.79 0 1.5-.31 2.04-.81l7.12 4.15c-.05.21-.08.43-.08.66 0 1.61 1.31 2.91 2.92 2.91s2.92-1.3 2.92-2.91A2.92 2.92 0 0 0 18 16.08"/></svg>
</a>
<button type="reset" class="md-search__icon md-icon" title="Clear" aria-label="Clear" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41 17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12z"/></svg>
</button>
</nav>
<div class="md-search__suggest" data-md-component="search-suggest"></div>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" tabindex="0" data-md-scrollfix>
<div class="md-search-result" data-md-component="search-result">
<div class="md-search-result__meta">
Initializing search
</div>
<ol class="md-search-result__list" role="presentation"></ol>
</div>
</div>
</div>
</div>
</div>
<div class="md-header__source">
<a href="https://github.com/trapexit/mergerfs" title="Go to repository" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><!--! Font Awesome Free 6.7.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2024 Fonticons, Inc.--><path d="M439.55 236.05 244 40.45a28.87 28.87 0 0 0-40.81 0l-40.66 40.63 51.52 51.52c27.06-9.14 52.68 16.77 43.39 43.68l49.66 49.66c34.23-11.8 61.18 31 35.47 56.69-26.49 26.49-70.21-2.87-56-37.34L240.22 199v121.85c25.3 12.54 22.26 41.85 9.08 55a34.34 34.34 0 0 1-48.55 0c-17.57-17.6-11.07-46.91 11.25-56v-123c-20.8-8.51-24.6-30.74-18.64-45L142.57 101 8.45 235.14a28.86 28.86 0 0 0 0 40.81l195.61 195.6a28.86 28.86 0 0 0 40.8 0l194.69-194.69a28.86 28.86 0 0 0 0-40.81"/></svg>
</div>
<div class="md-source__repository">
mergerfs
</div>
</a>
</div>
</nav>
</header>
<div class="md-container" data-md-component="container">
<main class="md-main" data-md-component="main">
<div class="md-main__inner md-grid">
<div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary" aria-label="Navigation" data-md-level="0">
<label class="md-nav__title" for="__drawer">
<a href="../.." title="mergerfs" class="md-nav__button md-logo" aria-label="mergerfs" data-md-component="logo">
<img src="../../logo.png" alt="logo">
</a>
mergerfs
</label>
<div class="md-nav__source">
<a href="https://github.com/trapexit/mergerfs" title="Go to repository" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512"><!--! Font Awesome Free 6.7.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2024 Fonticons, Inc.--><path d="M439.55 236.05 244 40.45a28.87 28.87 0 0 0-40.81 0l-40.66 40.63 51.52 51.52c27.06-9.14 52.68 16.77 43.39 43.68l49.66 49.66c34.23-11.8 61.18 31 35.47 56.69-26.49 26.49-70.21-2.87-56-37.34L240.22 199v121.85c25.3 12.54 22.26 41.85 9.08 55a34.34 34.34 0 0 1-48.55 0c-17.57-17.6-11.07-46.91 11.25-56v-123c-20.8-8.51-24.6-30.74-18.64-45L142.57 101 8.45 235.14a28.86 28.86 0 0 0 0 40.81l195.61 195.6a28.86 28.86 0 0 0 40.8 0l194.69-194.69a28.86 28.86 0 0 0 0-40.81"/></svg>
</div>
<div class="md-source__repository">
mergerfs
</div>
</a>
</div>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../.." class="md-nav__link">
<span class="md-ellipsis">
Home
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../quickstart/" class="md-nav__link">
<span class="md-ellipsis">
QuickStart
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3" >
<label class="md-nav__link" for="__nav_3" id="__nav_3_label" tabindex="0">
<span class="md-ellipsis">
Installation
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_3_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3">
<span class="md-nav__icon md-icon"></span>
Installation
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../setup/installation/" class="md-nav__link">
<span class="md-ellipsis">
Installation
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../setup/upgrade/" class="md-nav__link">
<span class="md-ellipsis">
Upgrade
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../setup/build/" class="md-nav__link">
<span class="md-ellipsis">
Build
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../../terminology/" class="md-nav__link">
<span class="md-ellipsis">
Terminology
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../intro_to_filesystems/" class="md-nav__link">
<span class="md-ellipsis">
Intro to Filesystems
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_6" checked>
<label class="md-nav__link" for="__nav_6" id="__nav_6_label" tabindex="0">
<span class="md-ellipsis">
Config
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_6_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_6">
<span class="md-nav__icon md-icon"></span>
Config
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item md-nav__item--active">
<input class="md-nav__toggle md-toggle" type="checkbox" id="__toc">
<label class="md-nav__link md-nav__link--active" for="__toc">
<span class="md-ellipsis">
Options
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
Options
</span>
</a>
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#types" class="md-nav__link">
<span class="md-ellipsis">
types
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#mount-options" class="md-nav__link">
<span class="md-ellipsis">
mount options
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../deprecated_options/" class="md-nav__link">
<span class="md-ellipsis">
Deprecated Options
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../branches/" class="md-nav__link">
<span class="md-ellipsis">
branches
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../branches_mount_timeout/" class="md-nav__link">
<span class="md-ellipsis">
branches-mount-timeout
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../functions_categories_policies/" class="md-nav__link">
<span class="md-ellipsis">
functions, categories and policies
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../minfreespace/" class="md-nav__link">
<span class="md-ellipsis">
minfreespace
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../func_readdir/" class="md-nav__link">
<span class="md-ellipsis">
func.readdir
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../rename_and_link/" class="md-nav__link">
<span class="md-ellipsis">
rename and link
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../moveonenospc/" class="md-nav__link">
<span class="md-ellipsis">
moveonenospc
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../cache/" class="md-nav__link">
<span class="md-ellipsis">
caching
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../readahead/" class="md-nav__link">
<span class="md-ellipsis">
readahead
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../inodecalc/" class="md-nav__link">
<span class="md-ellipsis">
inodecalc
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../threads/" class="md-nav__link">
<span class="md-ellipsis">
threads
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../pin-threads/" class="md-nav__link">
<span class="md-ellipsis">
pin-threads
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../link_cow/" class="md-nav__link">
<span class="md-ellipsis">
link_cow
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../fuse_msg_size/" class="md-nav__link">
<span class="md-ellipsis">
fuse_msg_size
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../follow-symlinks/" class="md-nav__link">
<span class="md-ellipsis">
follow-symlinks
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../link-exdev/" class="md-nav__link">
<span class="md-ellipsis">
link-exdev
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../rename-exdev/" class="md-nav__link">
<span class="md-ellipsis">
rename-exdev
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../symlinkify/" class="md-nav__link">
<span class="md-ellipsis">
symlinkify
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../nullrw/" class="md-nav__link">
<span class="md-ellipsis">
nullrw
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../xattr/" class="md-nav__link">
<span class="md-ellipsis">
xattr
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../nfsopenhack/" class="md-nav__link">
<span class="md-ellipsis">
nfsopenhack
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../statfs/" class="md-nav__link">
<span class="md-ellipsis">
statfs / statvfs
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../flush-on-close/" class="md-nav__link">
<span class="md-ellipsis">
flush-on-close
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../export-support/" class="md-nav__link">
<span class="md-ellipsis">
export-support
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../../error_handling_and_logging/" class="md-nav__link">
<span class="md-ellipsis">
Error Handling and Logging
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../runtime_interfaces/" class="md-nav__link">
<span class="md-ellipsis">
Runtime Interfaces
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../remote_filesystems/" class="md-nav__link">
<span class="md-ellipsis">
Remote Filesystems
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../tips_notes/" class="md-nav__link">
<span class="md-ellipsis">
Tips and Notes
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../known_issues_bugs/" class="md-nav__link">
<span class="md-ellipsis">
Known Issues and Bugs
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../project_comparisons/" class="md-nav__link">
<span class="md-ellipsis">
Project Comparisons
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../performance/" class="md-nav__link">
<span class="md-ellipsis">
Tweaking Performance
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../benchmarking/" class="md-nav__link">
<span class="md-ellipsis">
Benchmarking
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../tooling/" class="md-nav__link">
<span class="md-ellipsis">
Tooling
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../usage_patterns/" class="md-nav__link">
<span class="md-ellipsis">
Usage Patterns
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_17" >
<label class="md-nav__link" for="__nav_17" id="__nav_17_label" tabindex="0">
<span class="md-ellipsis">
FAQ
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_17_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_17">
<span class="md-nav__icon md-icon"></span>
FAQ
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../faq/why_isnt_it_working/" class="md-nav__link">
<span class="md-ellipsis">
"Why isn't it working?"
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/reliability_and_scalability/" class="md-nav__link">
<span class="md-ellipsis">
Reliability and Scalability
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/usage_and_functionality/" class="md-nav__link">
<span class="md-ellipsis">
Usage and Functionality
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/configuration_and_policies/" class="md-nav__link">
<span class="md-ellipsis">
Configuration and Policies
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/compatibility_and_integration/" class="md-nav__link">
<span class="md-ellipsis">
Compatibility and Integration
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/recommendations_and_warnings/" class="md-nav__link">
<span class="md-ellipsis">
Recommendations and Warnings
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/technical_behavior_and_limitations/" class="md-nav__link">
<span class="md-ellipsis">
Technical Behavior and Limitations
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/have_you_considered/" class="md-nav__link">
<span class="md-ellipsis">
"Have You Considered?"
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../faq/limit_drive_spinup/" class="md-nav__link">
<span class="md-ellipsis">
Limiting drive spinup
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../../related_projects/" class="md-nav__link">
<span class="md-ellipsis">
Related Projects
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../media_and_publicity/" class="md-nav__link">
<span class="md-ellipsis">
Media and Publicity
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../support/" class="md-nav__link">
<span class="md-ellipsis">
Support
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../sponsorship_and_donations/" class="md-nav__link">
<span class="md-ellipsis">
Sponsorship and Donations
</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-sidebar md-sidebar--secondary" data-md-component="sidebar" data-md-type="toc" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
Table of contents
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#types" class="md-nav__link">
<span class="md-ellipsis">
types
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#mount-options" class="md-nav__link">
<span class="md-ellipsis">
mount options
</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<a href="https://github.com/trapexit/mergerfs/edit/master/mkdocs/docs/config/options.md" title="Edit this page" class="md-content__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M10 20H6V4h7v5h5v3.1l2-2V8l-6-6H6c-1.1 0-2 .9-2 2v16c0 1.1.9 2 2 2h4zm10.2-7c.1 0 .3.1.4.2l1.3 1.3c.2.2.2.6 0 .8l-1 1-2.1-2.1 1-1c.1-.1.2-.2.4-.2m0 3.9L14.1 23H12v-2.1l6.1-6.1z"/></svg>
</a>
<a href="https://github.com/trapexit/mergerfs/raw/master/mkdocs/docs/config/options.md" title="View source of this page" class="md-content__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M17 18c.56 0 1 .44 1 1s-.44 1-1 1-1-.44-1-1 .44-1 1-1m0-3c-2.73 0-5.06 1.66-6 4 .94 2.34 3.27 4 6 4s5.06-1.66 6-4c-.94-2.34-3.27-4-6-4m0 6.5a2.5 2.5 0 0 1-2.5-2.5 2.5 2.5 0 0 1 2.5-2.5 2.5 2.5 0 0 1 2.5 2.5 2.5 2.5 0 0 1-2.5 2.5M9.27 20H6V4h7v5h5v4.07c.7.08 1.36.25 2 .49V8l-6-6H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h4.5a8.2 8.2 0 0 1-1.23-2"/></svg>
</a>
<h1 id="options">Options</h1>
<p>mergerfs has many options to control it many features. For the average
use case the options listed in the <a href="../../quickstart/">quickstart</a> are
sufficient. Most options are related to operating system or filesystem
related concepts so having a <a href="../../intro_to_filesystems/">basic
background</a> in such things is recommended
for more advanced configurations.</p>
<p>These option names and values are the same regardless of whether you
use them with the <code>mergerfs</code> commandline program, in fstab, or in a
config file.</p>
<h2 id="types">types</h2>
<ul>
<li>BOOL = 'true' | 'false'</li>
<li>INT = [MIN_INT,MAX_INT]</li>
<li>UINT = [0,MAX_INT]</li>
<li>SIZE = 'NNM'; NN = INT, M = 'B' | 'K' | 'M' | 'G' | 'T'</li>
<li>PAGESIZE = UINT (representing number of pages) | SIZE (in bytes
which will be converted to pages)</li>
<li>STR = string (may refer to an enumerated value, see details of
argument)</li>
<li>FUNC = filesystem <a href="../functions_categories_policies/">function</a></li>
<li>CATEGORY = function <a href="../functions_categories_policies/">category</a></li>
<li>POLICY = mergerfs function <a href="../functions_categories_policies/">policy</a></li>
</ul>
<h2 id="mount-options">mount options</h2>
<ul>
<li><strong>config</strong>: Path to a config file. Same arguments as below in
key=val / ini style format.</li>
<li><strong><a href="../branches/">branches</a></strong>: Colon delimited list of branches. Used
primarily in config file.</li>
<li><strong><a href="../minfreespace/">minfreespace</a>=SIZE</strong>: The minimum available
space of a branch necessary to be considered for a create
<a href="../functions_categories_policies/">policy</a>. This is a default value
applied to all branches and can be overwritten when configuring
<a href="../branches/">branches</a>. Understands 'K', 'M', and 'G' to represent
kilobyte, megabyte, and gigabyte respectively. (default: 4G)</li>
<li><strong><a href="../moveonenospc/">moveonenospc</a>=BOOL|POLICY</strong>: When enabled if a
<strong>write</strong> fails with <strong>ENOSPC</strong> (no space left on device) or
<strong>EDQUOT</strong> (disk quota exceeded) the policy selected will run to
find a new location for the file. An attempt to move the file to
that branch will occur (keeping all metadata possible) and if
successful the original is unlinked and the write retried. (default:
pfrd)</li>
<li><strong><a href="../inodecalc/">inodecalc</a>=passthrough|path-hash|devino-hash|hybrid-hash</strong>:
Selects the inode calculation algorithm. (default: hybrid-hash)</li>
<li><strong>dropcacheonclose=BOOL</strong>: When a file is requested to be closed
call <code>posix_fadvise</code> on it first to instruct the kernel that we no
longer need the data and it can drop its cache. Recommended when
<strong>cache.files=partial|full|auto-full|per-process</strong> to limit double
caching. (default: false)</li>
<li><strong>direct-io-allow-mmap=BOOL</strong>: On newer kernels (&gt;= 6.6) it is
possible to disable file page caching while still allowing for
shared mmap support. mergerfs will enable this feature if available
but an option is provided to turn it off for testing and debugging
purposes. (default: true)</li>
<li><strong><a href="../symlinkify/">symlinkify</a>=BOOL</strong>: When enabled and a file is not
writable and its mtime or ctime is older than <strong>symlinkify_timeout</strong>
files will be reported as symlinks to the original files. Please
read more below before using. (default: false)</li>
<li><strong><a href="../symlinkify/">symlinkify_timeout</a>=UINT</strong>: Time to wait, in
seconds, to activate the <strong>symlinkify</strong> behavior. (default: 3600)</li>
<li><strong>nullrw=BOOL</strong>: Turns reads and writes into no-ops. The request
will succeed but do nothing. Useful for benchmarking
mergerfs. (default: false)</li>
<li><strong>lazy-umount-mountpoint=BOOL</strong>: mergerfs will attempt to "lazy
umount" the mountpoint before mounting itself. Useful when
performing live upgrades of mergerfs. May not work on
FreeBSD. (default: false)</li>
<li><strong>ignorepponrename=BOOL</strong>: Ignore path preserving on
rename. Typically rename and link act differently depending on the
policy of <code>create</code> (read below). Enabling this will cause rename and
link to always use the non-path preserving behavior. This means
files, when renamed or linked, will stay on the same
filesystem. (default: false)</li>
<li><strong><a href="../export-support/">export-support</a>=BOOL</strong>: Sets a low-level FUSE
feature intended to indicate the filesystem can support being
exported via NFS. (default: true)</li>
<li><strong>security_capability=BOOL</strong>: If false return ENOATTR when xattr
security.capability is queried. (default: true)</li>
<li><strong><a href="../xattr/">xattr</a>=passthrough|noattr|nosys</strong>: Runtime control of
xattrs. Default is to passthrough xattr requests. 'noattr' will
short circuit as if nothing exists. 'nosys' will respond with ENOSYS
as if xattrs are not supported or disabled. (default: passthrough)</li>
<li><strong><a href="../link_cow/">link_cow</a>=BOOL</strong>: When enabled if a regular file is
opened which has a link count &gt; 1 it will copy the file to a
temporary file and rename over the original. Breaking the link and
providing a basic copy-on-write function similar to
cow-shell. (default: false)</li>
<li><strong><a href="../statfs/">statfs</a>=base|full</strong>: Controls how statfs works. 'base'
means it will always use all branches in statfs calculations. 'full'
is in effect path preserving and only includes branches where the
path exists. (default: base)</li>
<li><strong>statfs_ignore=none|ro|nc</strong>: 'ro' will cause statfs calculations to
ignore available space for branches mounted or tagged as 'read-only'
or 'no create'. 'nc' will ignore available space for branches tagged
as 'no create'. (default: none)</li>
<li><strong>nfsopenhack=off|git|all</strong>: A workaround for exporting mergerfs
over NFS where there are issues with creating files for write while
setting the mode to read-only. (default: off)</li>
<li><strong>branches-mount-timeout=UINT</strong>: Number of seconds to wait at
startup for branches to be a mount other than the mountpoint's
filesystem. (default: 0)</li>
<li><strong><a href="../follow-symlinks/">follow-symlinks</a>=never|directory|regular|all</strong>:
Turns symlinks into what they point to. (default: never)</li>
<li><strong><a href="../link-exdev/">link-exdev</a>=passthrough|rel-symlink|abs-base-symlink|abs-pool-symlink</strong>:
When a link fails with EXDEV optionally create a symlink to the file
instead.</li>
<li><strong><a href="../rename-exdev/">rename-exdev</a>=passthrough|rel-symlink|abs-symlink</strong>:
When a rename fails with EXDEV optionally move the file to a special
directory and symlink to it.</li>
<li><strong><a href="../readahead/">readahead</a>=UINT</strong>: Set readahead (in kilobytes) for
mergerfs and branches if greater than 0. (default: 0)</li>
<li><strong>posix_acl=BOOL</strong>: Enable POSIX ACL support (if supported by kernel
and underlying filesystem). (default: false)</li>
<li><strong>async_read=BOOL</strong>: Perform reads asynchronously. If disabled or
unavailable the kernel will ensure there is at most one pending read
request per file handle and will attempt to order requests by
offset. (default: true)</li>
<li><strong><a href="../fuse_msg_size/">fuse_msg_size</a>=PAGESIZE</strong>: Set the max number of
pages per FUSE message. Only available on Linux &gt;= 4.20 and ignored
otherwise. (min: 1; max: 65535; default: "1M")</li>
<li><strong><a href="../threads/">threads</a>=INT</strong>: Number of threads to use. When used
alone (<code>process-thread-count=-1</code>) it sets the number of threads
reading and processing FUSE messages. When used together it sets the
number of threads reading from FUSE. When set to zero it will
attempt to discover and use the number of logical cores. If the
thread count is set negative it will look up the number of cores
then divide by the absolute value. ie. threads=-2 on an 8 core
machine will result in 8 / 2 = 4 threads. There will always be at
least 1 thread. If set to -1 in combination with
<code>process-thread-count</code> then it will try to pick reasonable values
based on CPU thread count. NOTE: higher number of threads increases
parallelism but usually decreases throughput. (default: 0)</li>
<li><strong><a href="../threads/">read-thread-count</a>=INT</strong>: Alias for <code>threads</code>.</li>
<li><strong><a href="../threads/">process-thread-count</a>=INT</strong>: Enables separate thread
pool to asynchronously process FUSE requests. In this mode
<code>read-thread-count</code> refers to the number of threads reading FUSE
messages which are dispatched to process threads. -1 means disabled
otherwise acts like <code>read-thread-count</code>. (default: -1)</li>
<li><strong><a href="../threads/">process-thread-queue-depth</a>=UINT</strong>: Sets the number
of requests any single process thread can have queued up at one
time. Meaning the total memory usage of the queues is queue depth
multiplied by the number of process threads plus read thread
count. 0 sets the depth to the same as the process thread
count. (default: 0)</li>
<li><strong><a href="../pin-threads/">pin-threads</a>=STR</strong>: Selects a strategy to pin
threads to CPUs (default: unset)</li>
<li><strong><a href="../flush-on-close/">flush-on-close</a>=never|always|opened-for-write</strong>:
Flush data cache on file close. Mostly for when writeback is enabled
or merging network filesystems. (default: opened-for-write)</li>
<li><strong>scheduling-priority=INT</strong>: Set mergerfs' scheduling
priority. Valid values range from -20 to 19. See <code>setpriority</code> man
page for more details. (default: -10)</li>
<li><strong>fsname=STR</strong>: Sets the name of the filesystem as seen in
<strong>mount</strong>, <strong>df</strong>, etc. Defaults to a list of the source paths
concatenated together with the longest common prefix removed.</li>
<li><strong><a href="../functions_categories_policies/">func.FUNC</a>=POLICY</strong>: Sets the
specific FUSE function's policy. See below for the list of value
types. Example: <strong>func.getattr=newest</strong></li>
<li><strong><a href="../func_readdir/">func.readdir</a>=seq|cosr|cor|cosr:INT|cor:INT</strong>: Sets <code>readdir</code>
policy. INT value sets the number of threads to use for
concurrency. (default: seq)</li>
<li><strong><a href="../functions_categories_policies/">category.action</a>=POLICY</strong>: Sets
policy of all FUSE functions in the action category. (default:
epall)</li>
<li><strong><a href="../functions_categories_policies/">category.create</a>=POLICY</strong>: Sets
policy of all FUSE functions in the create category. (default:
pfrd)</li>
<li><strong><a href="../functions_categories_policies/">category.search</a>=POLICY</strong>: Sets
policy of all FUSE functions in the search category. (default: ff)</li>
<li><strong><a href="../cache/#cachestatfs">cache.statfs</a>=UINT</strong>: 'statfs' cache
timeout in seconds. (default: 0)</li>
<li><strong><a href="../cache/#cacheattr">cache.attr</a>=UINT</strong>: File attribute cache
timeout in seconds. (default: 1)</li>
<li><strong><a href="../cache/#cacheentry">cache.entry</a>=UINT</strong>: File name lookup cache
timeout in seconds. (default: 1)</li>
<li><strong><a href="../cache/#cachenegative_entry">cache.negative_entry</a>=UINT</strong>:
Negative file name lookup cache timeout in seconds. (default: 0)</li>
<li><strong><a href="../cache/#cachefiles">cache.files</a>=off|partial|full|auto-full|per-process</strong>:
File page caching mode (default: off)</li>
<li><strong>cache.files.process-names=LIST</strong>: A pipe | delimited list of
process <a href="https://man7.org/linux/man-pages/man5/proc.5.html">comm</a>
names to enable page caching for when
<code>cache.files=per-process</code>. (default: "rtorrent|qbittorrent-nox")</li>
<li><strong><a href="../cache/#cachewriteback">cache.writeback</a>=BOOL</strong>: Enable kernel
writeback caching (default: false)</li>
<li><strong><a href="../cache/#cachesymlinks">cache.symlinks</a>=BOOL</strong>: Cache symlinks (if
supported by kernel) (default: false)</li>
<li><strong><a href="../cache/#cachereaddir">cache.readdir</a>=BOOL</strong>: Cache readdir (if
supported by kernel) (default: false)</li>
<li><strong>parallel-direct-writes=BOOL</strong>: Allow the kernel to dispatch
multiple, parallel (non-extending) write requests for files opened
with <code>cache.files=per-process</code> (if the process is not in
<code>process-names</code>) or <code>cache.files=off</code>. (Is a kernel feature added in
v6.2) (default: true)</li>
</ul>
<p><strong>NOTE:</strong> Options are evaluated in the order listed so if the options
are <strong>func.rmdir=rand,category.action=ff</strong> the <strong>action</strong> category
setting will override the <strong>rmdir</strong> setting.</p>
<p><strong>NOTE:</strong> Always look at the documentation for the version of mergerfs
you're using. Not all features are available in older releases.</p>
</article>
</div>
<script>var target=document.getElementById(location.hash.slice(1));target&&target.name&&(target.checked=target.name.startsWith("__tabbed_"))</script>
</div>
<button type="button" class="md-top md-icon" data-md-component="top" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13 20h-2V8l-5.5 5.5-1.42-1.42L12 4.16l7.92 7.92-1.42 1.42L13 8z"/></svg>
Back to top
</button>
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="Footer" >
<a href="../../intro_to_filesystems/" class="md-footer__link md-footer__link--prev" aria-label="Previous: Intro to Filesystems">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
Previous
</span>
<div class="md-ellipsis">
Intro to Filesystems
</div>
</div>
</a>
<a href="../deprecated_options/" class="md-footer__link md-footer__link--next" aria-label="Next: Deprecated Options">
<div class="md-footer__title">
<span class="md-footer__direction">
Next
</span>
<div class="md-ellipsis">
Deprecated Options
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11z"/></svg>
</div>
</a>
</nav>
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
Made with
<a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
Material for MkDocs
</a>
</div>
</div>
</div>
</footer>
</div>
<div class="md-dialog" data-md-component="dialog">
<div class="md-dialog__inner md-typeset"></div>
</div>
<script id="__config" type="application/json">{"base": "../..", "features": ["content.action.edit", "content.action.view", "content.code.copy", "content.code.select", "navigation.footer", "navigation.instant", "navigation.instant.prefetch", "navigation.path", "navigation.top", "navigation.tracking", "optimize", "search.share", "search.suggest", "toc.follow"], "search": "../../assets/javascripts/workers/search.f8cc74c7.min.js", "tags": null, "translations": {"clipboard.copied": "Copied to clipboard", "clipboard.copy": "Copy to clipboard", "search.result.more.one": "1 more on this page", "search.result.more.other": "# more on this page", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents", "search.result.placeholder": "Type to start searching", "search.result.term.missing": "Missing", "select.version": "Select version"}, "version": null}</script>
<script src="../../assets/javascripts/bundle.c8b220af.min.js"></script>
</body>
</html>