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.
 
 
 
 

2067 lines
39 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/2.41.0-rc1/config/proxy-ioprio/">
<link rel="prev" href="../pin-threads/">
<link rel="next" href="../link_cow/">
<link rel="icon" href="../../logo.png">
<meta name="generator" content="mkdocs-1.6.1, mkdocs-material-9.6.21">
<title>proxy-ioprio - mergerfs</title>
<link rel="stylesheet" href="../../assets/stylesheets/main.2a3383ac.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="#proxy-ioprio" class="md-skip">
Skip to content
</a>
</div>
<div data-md-component="announce">
</div>
<div data-md-color-scheme="default" data-md-component="outdated" hidden>
</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">
proxy-ioprio
</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 7.0.1 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 2025 Fonticons, Inc.--><path d="M439.6 236.1 244 40.5c-5.4-5.5-12.8-8.5-20.4-8.5s-15 3-20.4 8.4L162.5 81l51.5 51.5c27.1-9.1 52.7 16.8 43.4 43.7l49.7 49.7c34.2-11.8 61.2 31 35.5 56.7-26.5 26.5-70.2-2.9-56-37.3L240.3 199v121.9c25.3 12.5 22.3 41.8 9.1 55-6.4 6.4-15.2 10.1-24.3 10.1s-17.8-3.6-24.3-10.1c-17.6-17.6-11.1-46.9 11.2-56v-123c-20.8-8.5-24.6-30.7-18.6-45L142.6 101 8.5 235.1C3 240.6 0 247.9 0 255.5s3 15 8.5 20.4l195.6 195.7c5.4 5.4 12.7 8.4 20.4 8.4s15-3 20.4-8.4l194.7-194.7c5.4-5.4 8.4-12.8 8.4-20.4s-3-15-8.4-20.4"/></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 7.0.1 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 2025 Fonticons, Inc.--><path d="M439.6 236.1 244 40.5c-5.4-5.5-12.8-8.5-20.4-8.5s-15 3-20.4 8.4L162.5 81l51.5 51.5c27.1-9.1 52.7 16.8 43.4 43.7l49.7 49.7c34.2-11.8 61.2 31 35.5 56.7-26.5 26.5-70.2-2.9-56-37.3L240.3 199v121.9c25.3 12.5 22.3 41.8 9.1 55-6.4 6.4-15.2 10.1-24.3 10.1s-17.8-3.6-24.3-10.1c-17.6-17.6-11.1-46.9 11.2-56v-123c-20.8-8.5-24.6-30.7-18.6-45L142.6 101 8.5 235.1C3 240.6 0 247.9 0 255.5s3 15 8.5 20.4l195.6 195.7c5.4 5.4 12.7 8.4 20.4 8.4s15-3 20.4-8.4l194.7-194.7c5.4-5.4 8.4-12.8 8.4-20.4s-3-15-8.4-20.4"/></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">
<a href="../options/" class="md-nav__link">
<span class="md-ellipsis">
Options
</span>
</a>
</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="../passthrough/" class="md-nav__link">
<span class="md-ellipsis">
passthrough
</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 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">
proxy-ioprio
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
proxy-ioprio
</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="#conflicts-with-other-options" class="md-nav__link">
<span class="md-ellipsis">
Conflicts With Other Options
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#supported-platforms" class="md-nav__link">
<span class="md-ellipsis">
Supported Platforms
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#performance-impact" class="md-nav__link">
<span class="md-ellipsis">
Performance Impact
</span>
</a>
</li>
</ul>
</nav>
</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>
<li class="md-nav__item">
<a href="../kernel-permissions-check/" class="md-nav__link">
<span class="md-ellipsis">
kernel-permissions-check
</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="../../resource_usage/" class="md-nav__link">
<span class="md-ellipsis">
Resource Usage and Management
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../runtime_interface/" class="md-nav__link">
<span class="md-ellipsis">
Runtime Interface
</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="../../benchmarking/" class="md-nav__link">
<span class="md-ellipsis">
Benchmarking
</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="../../tooling/" class="md-nav__link">
<span class="md-ellipsis">
Tooling
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../extended_usage_patterns/" class="md-nav__link">
<span class="md-ellipsis">
Extended 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_18" >
<label class="md-nav__link" for="__nav_18" id="__nav_18_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_18_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_18">
<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="#conflicts-with-other-options" class="md-nav__link">
<span class="md-ellipsis">
Conflicts With Other Options
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#supported-platforms" class="md-nav__link">
<span class="md-ellipsis">
Supported Platforms
</span>
</a>
</li>
<li class="md-nav__item">
<a href="#performance-impact" class="md-nav__link">
<span class="md-ellipsis">
Performance Impact
</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/proxy-ioprio.md" title="Edit this page" class="md-content__button md-icon" rel="edit">
<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/proxy-ioprio.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="proxy-ioprio">proxy-ioprio</h1>
<ul>
<li>type: <code>BOOL</code></li>
<li>default: <code>false</code></li>
<li>example: <code>proxy-ioprio=true</code></li>
</ul>
<p>In Linux certain process schedulers have the ability to
<a href="https://man7.org/linux/man-pages/man2/ioprio_set.2.html">prioritize</a>
based on a per thread <a href="https://www.kernel.org/doc/Documentation/block/ioprio.txt">IO
priority</a>
assigned to the software by users using tools such as
<a href="https://man7.org/linux/man-pages/man1/ionice.1.html">ionice</a>. Since
such details are not provided by the FUSE protocol, users may not use
schedulers which support IO priority, and the extra overhead to query
the priority and set it within mergerfs it does not by default attempt
to mirror/proxy the value. When enabled however, for all read and
write requests, mergerfs will query the priority of the requesting
process/thread and set the same value on the thread within mergerfs
making the read/write.</p>
<p>This may be useful in situation where the system has high IO load or
processes are known to have varying priorities. See the <a href="https://man7.org/linux/man-pages/man2/ioprio_set.2.html">man
page</a> for
specific details.</p>
<p>Keep in mind that if no IO scheduler has been set for a thread then by
default the IO priority will match the CPU nice value which for
mergerfs is set by <a href="../options/">scheduling-priority</a>. <a href="https://man7.org/linux/man-pages/man2/getpriority.2.html">Nice
value</a>
proxying may be added in a future release.</p>
<h2 id="conflicts-with-other-options">Conflicts With Other Options</h2>
<p>If using <a href="../passthrough/">IO passthrough</a> there is no reason to set
this value to <code>true</code>. However, since <code>passthrough</code> leads to mergerfs
IO calls being bypassed entirely will have no impact on performance or
behavior regardless.</p>
<p>When using <code>passthrough</code> the IO priority of the client app would be
used directly given the IO is passed through.</p>
<h2 id="supported-platforms">Supported Platforms</h2>
<p>Only Linux. This is not supported on FreeBSD.</p>
<h2 id="performance-impact">Performance Impact</h2>
<p>Despite the additional syscalls requires the impact appears
undetectable with larger buffer sizes. At very small buffer sizes
(such as 512 bytes) there is a noticable but small impact (~1.5%).</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="../pin-threads/" class="md-footer__link md-footer__link--prev" aria-label="Previous: pin-threads">
<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">
pin-threads
</div>
</div>
</a>
<a href="../link_cow/" class="md-footer__link md-footer__link--next" aria-label="Next: link_cow">
<div class="md-footer__title">
<span class="md-footer__direction">
Next
</span>
<div class="md-ellipsis">
link_cow
</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.973d3a69.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": {"provider": "mike"}}</script>
<script src="../../assets/javascripts/bundle.f55a23d4.min.js"></script>
</body>
</html>