GRUB Boot from ISO | Linux Journal

<!DOCTYPE html> <html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# " class="no-js wf-loading"> <head> <meta charset="utf-8" /> <meta name="Generator" content="Drupal 9 (https://www.drupal.org)" /> <meta name="MobileOptimized" content="width" /> <meta name="HandheldFriendly" content="true" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <link rel="icon" href="/themes/linuxjournal/favicon.ico" type="image/vnd.microsoft.icon" /> <link rel="canonical" href="https://www.linuxjournal.com/content/grub-boot-iso" /> <link rel="shortlink" href="https://www.linuxjournal.com/node/1339316" /> <title>GRUB Boot from ISO | Linux Journal</title> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/align.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/fieldgroup.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/container-inline.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/clearfix.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/details.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/hidden.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/item-list.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/js.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/nowrap.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/position-container.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/progress.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/reset-appearance.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/resize.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/sticky-header.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/system-status-counter.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/system-status-report-counters.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/system-status-report-general-info.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/tablesort.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/system/css/components/tree-child.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/modules/contrib/poll/css/poll.base.css?smwnh4" /> <link rel="stylesheet" media="all" href="/modules/contrib/poll/css/poll.theme.css?smwnh4" /> <link rel="stylesheet" media="all" href="/core/modules/views/css/views.module.css?smwnh4" /> <link rel="stylesheet" media="all" href="/libraries/shariff/shariff.complete.css?smwnh4" /> <link rel="stylesheet" media="all" href="/modules/contrib/webform/modules/webform_bootstrap/css/webform_bootstrap.css?smwnh4" /> <link rel="stylesheet" media="all" href="/themes/linuxjournal/css/style.css?smwnh4" /> <link rel="stylesheet" media="all" href="/themes/linuxjournal/css/fonts.css?smwnh4" />  <script> // Non-blocking webfonts. (function iife() { 'use strict'; // JS is able to start executing. document.documentElement.classList.remove('no-js'); // Optimization for Repeat Views // Stop early for repeat views that have already cached fonts. if (sessionStorage.fontsLoadedLateef && sessionStorage.fontsLoadedOpensans /* && sessionStorage.fontsLoadedNEWFONT */) { document.documentElement.classList.remove('wf-loading'); document.documentElement.classList.add('wf-opensans'); document.documentElement.classList.add('wf-lateef'); // document.documentElement.classList.add('wf-NEWFONT'); return; } // Inlined Font Face Observer script + Promise polyfill. /*! Font Face Observer v2.0.13 - © Bram Stein. License: BSD-3-Clause */ (function(){'use strict';var f,g=[];function l(a){g.push(a);1==g.length&&f()}function m(){for(;g.length;)g[0](),g.shift()}f=function(){setTimeout(m)};function n(a){this.a=p;this.b=void 0;this.f=[];var b=this;try{a(function(a){q(b,a)},function(a){r(b,a)})}catch(c){r(b,c)}}var p=2;function t(a){return new n(function(b,c){c(a)})}function u(a){return new n(function(b){b(a)})}function q(a,b){if(a.a==p){if(b==a)throw new TypeError;var c=!1;try{var d=b&&b.then;if(null!=b&&"object"==typeof b&&"function"==typeof d){d.call(b,function(b){c||q(a,b);c=!0},function(b){c||r(a,b);c=!0});return}}catch(e){c||r(a,e);return}a.a=0;a.b=b;v(a)}} function r(a,b){if(a.a==p){if(b==a)throw new TypeError;a.a=1;a.b=b;v(a)}}function v(a){l(function(){if(a.a!=p)for(;a.f.length;){var b=a.f.shift(),c=b[0],d=b[1],e=b[2],b=b[3];try{0==a.a?"function"==typeof c?e(c.call(void 0,a.b)):e(a.b):1==a.a&&("function"==typeof d?e(d.call(void 0,a.b)):b(a.b))}catch(h){b(h)}}})}n.prototype.g=function(a){return this.c(void 0,a)};n.prototype.c=function(a,b){var c=this;return new n(function(d,e){c.f.push([a,b,d,e]);v(c)})}; function w(a){return new n(function(b,c){function d(c){return function(d){h[c]=d;e+=1;e==a.length&&b(h)}}var e=0,h=[];0==a.length&&b(h);for(var k=0;k<a.length;k+=1)u(a[k]).c(d(k),c)})}function x(a){return new n(function(b,c){for(var d=0;d<a.length;d+=1)u(a[d]).c(b,c)})};window.Promise||(window.Promise=n,window.Promise.resolve=u,window.Promise.reject=t,window.Promise.race=x,window.Promise.all=w,window.Promise.prototype.then=n.prototype.c,window.Promise.prototype["catch"]=n.prototype.g);}()); (function(){function l(a,b){document.addEventListener?a.addEventListener("scroll",b,!1):a.attachEvent("scroll",b)}function m(a){document.body?a():document.addEventListener?document.addEventListener("DOMContentLoaded",function c(){document.removeEventListener("DOMContentLoaded",c);a()}):document.attachEvent("onreadystatechange",function k(){if("interactive"==document.readyState||"complete"==document.readyState)document.detachEvent("onreadystatechange",k),a()})};function r(a){this.a=document.createElement("div");this.a.setAttribute("aria-hidden","true");this.a.appendChild(document.createTextNode(a));this.b=document.createElement("span");this.c=document.createElement("span");this.h=document.createElement("span");this.f=document.createElement("span");this.g=-1;this.b.style.cssText="max-width:none;display:inline-block;position:absolute;height:100%;width:100%;overflow:scroll;font-size:16px;";this.c.style.cssText="max-width:none;display:inline-block;position:absolute;height:100%;width:100%;overflow:scroll;font-size:16px;"; this.f.style.cssText="max-width:none;display:inline-block;position:absolute;height:100%;width:100%;overflow:scroll;font-size:16px;";this.h.style.cssText="display:inline-block;width:200%;height:200%;font-size:16px;max-width:none;";this.b.appendChild(this.h);this.c.appendChild(this.f);this.a.appendChild(this.b);this.a.appendChild(this.c)} function t(a,b){a.a.style.cssText="max-width:none;min-width:20px;min-height:20px;display:inline-block;overflow:hidden;position:absolute;width:auto;margin:0;padding:0;top:-999px;white-space:nowrap;font-synthesis:none;font:"+b+";"}function y(a){var b=a.a.offsetWidth,c=b+100;a.f.style.width=c+"px";a.c.scrollLeft=c;a.b.scrollLeft=a.b.scrollWidth+100;return a.g!==b?(a.g=b,!0):!1}function z(a,b){function c(){var a=k;y(a)&&a.a.parentNode&&b(a.g)}var k=a;l(a.b,c);l(a.c,c);y(a)};function A(a,b){var c=b||{};this.family=a;this.style=c.style||"normal";this.weight=c.weight||"normal";this.stretch=c.stretch||"normal"}var B=null,C=null,E=null,F=null;function G(){if(null===C)if(J()&&/Apple/.test(window.navigator.vendor)){var a=/AppleWebKit\/([0-9]+)(?:\.([0-9]+))(?:\.([0-9]+))/.exec(window.navigator.userAgent);C=!!a&&603>parseInt(a[1],10)}else C=!1;return C}function J(){null===F&&(F=!!document.fonts);return F} function K(){if(null===E){var a=document.createElement("div");try{a.style.font="condensed 100px sans-serif"}catch(b){}E=""!==a.style.font}return E}function L(a,b){return[a.style,a.weight,K()?a.stretch:"","100px",b].join(" ")} A.prototype.load=function(a,b){var c=this,k=a||"BESbswy",q=0,D=b||3E3,H=(new Date).getTime();return new Promise(function(a,b){if(J()&&!G()){var M=new Promise(function(a,b){function e(){(new Date).getTime()-H>=D?b():document.fonts.load(L(c,'"'+c.family+'"'),k).then(function(c){1<=c.length?a():setTimeout(e,25)},function(){b()})}e()}),N=new Promise(function(a,c){q=setTimeout(c,D)});Promise.race([N,M]).then(function(){clearTimeout(q);a(c)},function(){b(c)})}else m(function(){function u(){var b;if(b=-1!= f&&-1!=g||-1!=f&&-1!=h||-1!=g&&-1!=h)(b=f!=g&&f!=h&&g!=h)||(null===B&&(b=/AppleWebKit\/([0-9]+)(?:\.([0-9]+))/.exec(window.navigator.userAgent),B=!!b&&(536>parseInt(b[1],10)||536===parseInt(b[1],10)&&11>=parseInt(b[2],10))),b=B&&(f==v&&g==v&&h==v||f==w&&g==w&&h==w||f==x&&g==x&&h==x)),b=!b;b&&(d.parentNode&&d.parentNode.removeChild(d),clearTimeout(q),a(c))}function I(){if((new Date).getTime()-H>=D)d.parentNode&&d.parentNode.removeChild(d),b(c);else{var a=document.hidden;if(!0===a||void 0===a)f=e.a.offsetWidth, g=n.a.offsetWidth,h=p.a.offsetWidth,u();q=setTimeout(I,50)}}var e=new r(k),n=new r(k),p=new r(k),f=-1,g=-1,h=-1,v=-1,w=-1,x=-1,d=document.createElement("div");d.dir="ltr";t(e,L(c,"sans-serif"));t(n,L(c,"serif"));t(p,L(c,"monospace"));d.appendChild(e.a);d.appendChild(n.a);d.appendChild(p.a);document.body.appendChild(d);v=e.a.offsetWidth;w=n.a.offsetWidth;x=p.a.offsetWidth;I();z(e,function(a){f=a;u()});t(e,L(c,'"'+c.family+'",sans-serif'));z(n,function(a){g=a;u()});t(n,L(c,'"'+c.family+'",serif')); z(p,function(a){h=a;u()});t(p,L(c,'"'+c.family+'",monospace'))})})};"object"===typeof module?module.exports=A:(window.FontFaceObserver=A,window.FontFaceObserver.prototype.load=A.prototype.load);}()); // Load and observe Lateef var Lateef = new FontFaceObserver('Lateef', {weight: 400}); Promise.all([Lateef.load()]).then(function() { document.documentElement.classList.remove('wf-loading'); document.documentElement.classList.add('wf-lateef'); // Optimization for Repeat Views // Set a flag in localstorage so repeat views can skip processing FFO. sessionStorage.fontsLoadedLateef = true; }); // Load and observe Open Sans var os300 = new FontFaceObserver('Open Sans', {weight: 300}); var os400 = new FontFaceObserver('Open Sans', {weight: 400}); Promise.all([os300.load(), os400.load()]).then(function() { document.documentElement.classList.remove('wf-loading'); document.documentElement.classList.add('wf-opensans'); // Optimization for Repeat Views // Set a flag in localstorage so repeat views can skip processing FFO. sessionStorage.fontsLoadedOpensans = true; }); // Load and observe NEWFONT /* var NEWFONT = new FontFaceObserver('NEWFONT', {weight: 400}); Promise.all([NEWFONT.load()]).then(function() { document.documentElement.classList.remove('wf-loading'); document.documentElement.classList.add('wf-NEWFONT'); // Optimization for Repeat Views // Set a flag in localstorage so repeat views can skip processing FFO. sessionStorage.fontsLoadedNEWFONT = true; }); */ })(); </script> <script src="https://www.google.com/recaptcha/api.js" async defer></script> <script src=https://slashdot.org/country.js></script> <script src="/themes/linuxjournal/js/ada.js"></script> <script src="/themes/linuxjournal/js/accessibility.js"></script> <script>window.addEventListener('load', function() { new Accessibility(); });</script> <script src="//a.fsdn.com/con/js/sftheme/cmp2.js"></script> <link rel="stylesheet" href="//a.fsdn.com/con/css/sftheme/sandiego/cmp.css" type="text/css"> <link rel="stylesheet" href="/themes/linuxjournal/css/ccpa.css" type="text/css"> <script>window.bizx.cmp.init({ geo: window });</script> <script> function bm_trace() { (function (w,d,t) { _ml = w._ml || {}; _ml.eid = '771'; var s, cd, tag; s = d.getElementsByTagName(t)[0]; cd = new Date(); tag = d.createElement(t); tag.async = 1; tag.src = 'https://ml314.com/tag.aspx?' + cd.getDate() + cd.getMonth(); s.parentNode.insertBefore(tag, s); })(window,document,'script'); } bizx.cmp.ifConsent('', ['all', 'bombora'],bm_trace); </script> </head> <body class="path-node page-node-type-story has-glyphicons"> <a href="#main-content" class="visually-hidden focusable skip-link"> Skip to main content </a> <div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas> <div id="wrap"> <div class="leader-wrapper" id="leader-wrapper"> </div> <div class="brand-wrapper" id="brand-wrapper"> <div class="brand container"> <div class="region region-brand"> <a class="logo navbar-btn" href="/" title="Home" rel="home"> <h1><img src="/themes/linuxjournal/images/ljlogo.png" alt="Linux Journal" /></h1> </a> <section id="block-topbannernearlogo" class="block block-block-content block-block-contenta8e75a3d-967c-416d-8944-4015d1f90a84 clearfix"> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><a href="https://www.windriver.com/products/elxr-pro?utm_source=ba&utm_medium=pa&utm_campaign=ba-dg-amer-awa-vsmf-eLxrProLau_lin_dis_09172024"><img alt="Windriver eLxrPro" data-entity-type="file" data-entity-uuid="8ba04368-7803-4329-a196-dc1ea780ec2a" src="/sites/default/files/inline-images/WindRiver-eLxrPro_0.png" width="728" height="90" loading="lazy" /></a></div> </section> </div> </div> <div class="header-wrapper"> <header class="navbar navbar-default container" id="navbar" role="banner"> <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#navbar-collapse"> <span class="sr-only">Toggle navigation</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> <div id="navbar-collapse" class="navbar-collapse collapse"> <div class="region region-navigation-collapsible"> <section id="block-linuxjournal-main-menu" class="block block-system block-system-menu-blockmain clearfix navbar__menu col-xs-12 col-sm-8"> <ul class="menu menu--main nav navbar-nav"> <li class="expanded dropdown first"> <a href="/" class="dropdown-toggle" data-toggle="dropdown" data-drupal-link-system-path="<front>">Topics+ <span class="caret"></span></a> <ul class="dropdown-menu"> <li class="first"> <a href="/tag/cloud">Cloud</a> </li> <li> <a href="/tag/containers" data-drupal-link-system-path="taxonomy/term/978">Containers</a> </li> <li> <a href="/tag/desktop">Desktop</a> </li> <li> <a href="/tag/kernel" data-drupal-link-system-path="taxonomy/term/662">Kernel</a> </li> <li> <a href="/tag/mobile">Mobile</a> </li> <li> <a href="/tag/networking">Networking</a> </li> <li> <a href="/tag/privacy">Privacy</a> </li> <li> <a href="/tag/programming">Programming</a> </li> <li> <a href="/tag/security" data-drupal-link-system-path="taxonomy/term/31">Security</a> </li> <li> <a href="/tag/servers">Servers</a> </li> <li class="last"> <a href="/tag/sysadmin" data-drupal-link-system-path="taxonomy/term/21">SysAdmin</a> </li> </ul> </li> <li> <a href="/news" data-drupal-link-system-path="news">News</a> </li> <li class="last"> <a href="/books" data-drupal-link-system-path="books">eBooks</a> </li> </ul> </section> <section class="search-block-form block block-search block-search-form-block clearfix navbar__search col-xs-12 col-sm-4 col-md-4 col-md-offset-0" data-drupal-selector="search-block-form" id="block-linuxjournal-search" role="search"> <h2 class="block-title sr-only">Search</h2> <form action="/search/node" method="get" id="search-block-form" accept-charset="UTF-8"> <div class="form-item js-form-item form-type-search js-form-type-search form-item-keys js-form-item-keys form-no-label form-group"> <label for="edit-keys" class="control-label sr-only">Search</label> <div class="input-group"><input title="Enter the terms you wish to search for." data-drupal-selector="edit-keys" class="form-search form-control" placeholder="Search" type="search" id="edit-keys" name="keys" value="" size="15" maxlength="128" /><span class="input-group-btn"><button type="submit" value="Search" class="button js-form-submit form-submit btn-primary btn icon-only" name=""><span class="sr-only">Search</span><span class="icon glyphicon glyphicon-search" aria-hidden="true"></span></button></span></div> <div id="edit-keys--description" class="description help-block"> Enter the terms you wish to search for. </div> </div> <div class="form-actions form-group js-form-wrapper form-wrapper" data-drupal-selector="edit-actions" id="edit-actions"></div> </form> </section> </div> </div> <div class="navbar-header"> <div class="region region-navigation"> <section id="block-mobilenavigation" class="block block-system block-system-menu-blockmenu-mobile-navbar clearfix col-xs-12 col-md-8 col-md-offset-2 col-lg-8 col-lg-offset-0 navbar__menu navbar__mobilenavigation"> <ul class="menu menu--menu-mobile-navbar nav"> <li class="first"> <a href="/news" data-drupal-link-system-path="news">News</a> </li> <li> <a href="/popular" data-drupal-link-system-path="popular">Popular</a> </li> <li class="last"> <a href="/recent" data-drupal-link-system-path="recent">Recent</a> </li> </ul> </section> </div> </div> </header> </div> </div> <div role="main" class="main-container container js-quickedit-main-content" id="main"> <div class="row"> <section class="col-sm-12"> <div class="highlighted"> <div class="region region-highlighted"> <div data-drupal-messages-fallback class="hidden"></div> </div> </div> <a id="main-content"></a> <div class="region region-content"> <article data-history-node-id="1339316" class="row bs-2col-stacked node node--type-story node--view-mode-full"> <div class="col-sm-12 bs-region bs-region--top"> <div class="field field--name-field-tags field--type-entity-reference field--label-hidden field--items"> <div class="field--item"><div about="/tag/grub" typeof="schema:Thing"> <h2><a href="/tag/grub"> <div property="schema:name" class="field field--name-name field--type-string field--label-hidden field--item">GRUB</div> </a></h2> <span property="schema:name" content="GRUB" class="hidden"></span> </div> </div> <div class="field--item"><div about="/tag/how-tos" typeof="schema:Thing"> <h2><a href="/tag/how-tos"> <div property="schema:name" class="field field--name-name field--type-string field--label-hidden field--item">HOW-TOs</div> </a></h2> <span property="schema:name" content="HOW-TOs" class="hidden"></span> </div> </div> </div> <div class="field field--name-node-title field--type-ds field--label-hidden field--item"><h1> GRUB Boot from ISO </h1> </div> <div class="field field--name-node-author field--type-ds field--label-hidden field--item">by <a title="View user profile." href="/users/kyle-rankin" lang="" about="/users/kyle-rankin" typeof="schema:Person" property="schema:name" datatype="">Kyle Rankin</a></div> <div class="field field--name-node-post-date field--type-ds field--label-hidden field--item">on March 14, 2017</div> </div> <div class="col-sm-9 bs-region bs-region--left"> <div class="shariff" data-services="["twitter","facebook","linkedin","reddit","mail"]" data-theme="white" data-css="complete" data-orientation="horizontal" data-twitter-via="linuxjournal" data-mail-url="mailto:" data-lang="en"> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p> Last year I worked on a project to add an OEM-style rescue partition to a computer. Where most OEM installs have a custom program that just rewrites an install image over the top of the partition, in this case, everything was based on open-source software. This rescue partition would be only a few gigabytes in size—big enough to contain the install DVD ISO image and a few preseed files to help automate the install. If users ever wanted to get back to the factory-installed version of the operating system, they could select a special option from the GRUB menu that would boot off the ISO and start the install as though they had used a USB key or DVD. </p> <p> If you read some past guides on how to boot an ISO from GRUB, you will find a number of pretty complicated instructions in some cases because they were writing for older versions of GRUB. With the recent versions of GRUB2, booting from a standard ISO is fortunately not that complicated. I base my example here off a recent Debian Stretch install DVD, but the same steps should work for other distributions and install ISOs with some tweaks. </p> <span class="h3-replacement"> Create the Partition</span> <p> The first step is to create the rescue partition. In my case, I automated my install with a preseed script, but basically I just created a partition that was big enough to hold the install DVD. I made sure to give it a label so I could tell it apart from other disks later on and made it the second partition on the disk. Because I was doing all of this via an automated means, I ended up using <code>dd</code> to create an image of the install DVD that was currently in use as an end-of-install script and dumped it to the root of that partition in a file called install_dvd1.iso. Of course, you could just copy over your ISO directly to the disk if you do this from a system that already has an OS on it. </p> <span class="h3-replacement"> Build the GRUB Config</span> <p> The next step was to build a GRUB config that would mount the ISO loopback and boot off the kernel and initrd file within that ISO. On Debian-based systems, you can add bash scripts that output extra GRUB configuration to /etc/grub.d/ and run <code>update-grub</code> to build a new grub.cfg file. But, you also could just edit grub.cfg directly or otherwise use your distribution's GRUB configuration scripts to add the following menu items: </p><pre> <code> set root='hd0,msdos2' set isofile="/install_dvd1.iso" menuentry "Install OS" { loopback loop (hd0,msdos2)$isofile linux (loop)/install.amd/vmlinuz vga=788 auto=true ↪file=/media/preseed.cfg -- quiet initrd (loop)/install.amd/initrd.gz } menuentry "Install OS (Expert)" { loopback loop (hd0,msdos2)$isofile linux (loop)/install.amd/vmlinuz vga=788 -- quiet initrd (loop)/install.amd/initrd.gz } </code> </pre> <p> Let's break this GRUB configuration down a bit. First, you set two variables: the root partition GRUB will use (the second partition on the first disk, which GRUB refers to as hd0,msdos2) and the ISO file: </p><pre> <code> set root='hd0,msdos2' set isofile="/install_dvd1.iso" </code> </pre> <p> Next are two separate GRUB menus (each are within <code>menuentry {}</code> stanzas). The first points to a preseed configuration file and starts a partially automated Debian install, while the other just boots the Debian installer with no preseed file and acts like an "Expert" mode so you can choose every install option by hand. </p> <p> Up to this point, the GRUB options were pretty similar to other GRUB configurations, but here is where that changes. Next in each menu, you define a loopback device GRUB will use: </p><pre> <code> loopback loop (hd0,msdos2)$isofile </code> </pre> <p> Now, whenever you refer to <code>(loop)</code> further in the config, GRUB knows to access the loopback filesystem labeled loop, which points to (hd0,msdos2)/install_dvd1.iso. The next two lines should look pretty familiar to someone who has worked with Linux GRUB configuration before, but with a twist: </p><pre> <code> linux (loop)/install.amd/vmlinuz vga=788 auto=true ↪file=/media/preseed.cfg -- quiet initrd (loop)/install.amd/initrd.gz </code> </pre> <p> In the first line, you define what kernel to boot and what options to pass it, and in the following line, you point GRUB to the initrd file you want it to use. The main difference here though is that you precede each file path with <code>(loop)</code> to instruct GRUB to look in that loopback filesystem for the file. </p> <p> Once this configuration finds its way into grub.cfg, you should see the two new menu options in place the next time you boot. Now the first time I tried to boot the most recent Debian installer this way, I ran into a bit of a problem. It turns out that the initrd that comes on the ISO itself does not contain the installer scripts you need to install from an ISO on a hard drive. It assumes you will boot only off a DVD or USB disk. Because of that, I discovered I had to download a different Debian installer initrd and put it on the rescue disk for things to work. I was able to find an initrd that worked <a href="http://mirrors.kernel.org/debian/dists/stretch/main/installer-amd64/current/images/hd-media/initrd.gz">here</a>. </p> <p> Of course, with that new initrd.gz file at the root of my rescue partition, I had to change my GRUB config a little bit to point to it: </p><pre> <code> set root='hd0,msdos2' set isofile="/install_dvd1.iso" menuentry "Install OS" { loopback loop (hd0,msdos2)$isofile linux (loop)/install.amd/vmlinuz vga=788 auto=true ↪file=/media/preseed.cfg -- quiet initrd /initrd.gz } menuentry "Install OS (Expert)" { loopback loop (hd0,msdos2)$isofile linux (loop)/install.amd/vmlinuz vga=788 -- quiet initrd /initrd.gz } </code> </pre> <p> Note that the initrd lines now point to /initrd.gz. Since I already defined the root variable earlier in the config, it knows to look on hd0,msdos2 for the file. Once this new initrd was in place, I was in business, and the installer worked as expected. If you want to use this with a different installer, just make sure that once the kernel boots up, it has the ability to scan disks for an installer ISO to use. </p></div> <div class="field field--name-dynamic-token-fieldnode-author field--type-ds field--label-hidden field--item"><div> <img loading="lazy" src="/sites/default/files/pictures/picture-1002206.jpg" width="85" height="84" typeof="foaf:Image" class="img-responsive" /> </div> <p> Kyle Rankin is a Tech Editor and columnist at <em>Linux Journal</em> and the Chief Security Officer at Purism. He is the author of <em>Linux Hardening in Hostile Networks</em>, <em>DevOps Troubleshooting</em>, <em>The Official Ubuntu Server Book</em>, <em>Knoppix Hacks</em>, <em>Knoppix Pocket Reference</em>, <em>Linux Multimedia Hacks</em> and <em>Ubuntu Hacks</em>, and also a contributor to a number of other O'Reilly books. Rankin speaks frequently on security and open-source software including at BsidesLV, O'Reilly Security Conference, OSCON, SCALE, CactusCon, Linux World Expo and Penguicon. You can follow him at @kylerankin. </p> </div> <section class="section--disqus"> <a id="comments-link" class="btn btn-default" href="https://www.linuxjournal.com/content/grub-boot-iso#disqus_thread">Load Disqus comments</a> <div id="disqus_thread"></div> <noscript>Our discussions are <a href="https://disqus.com/?ref_noscript" rel="nofollow">powered by Disqus</a>, which require JavaScript.</noscript> </section> </div> <div class="col-sm-3 bs-region bs-region--right"> <div class="field field--name-dynamic-block-fieldnode-sidebar-image field--type-ds field--label-hidden field--item"><div class="views-element-container form-group"><div class="view view-sidebar-image view-id-sidebar_image view-display-id-block_1 js-view-dom-id-11fd6fdf4229602ad8883dc646f1c8b9e5f53abf59a9c9f9e07ca35f0f596e4b"> </div> </div> </div> <div class="field field--name-dynamic-block-fieldnode-recent-content field--type-ds field--label-hidden field--item"><div class="views-element-container form-group"><div class="view view-related-content view-id-related_content view-display-id-block_2 js-view-dom-id-d3b92c769b9c68a6572b6d5d110a89d93aa652130fe0957d385249af35d0c042"> <div class="view-header"> <h2 class="block-title">Recent Articles</h2> </div> <div class="view-content"> <div class="views-row"><div class="views-field views-field-field-node-image"><div class="field-content"> <a href="/content/using-maxqda-qualitative-data-analysis-linux" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/75x75_square/public/nodeimage/story/using-maxqda-for-qualitative-data-analysis-on-linux.jpg?itok=KFsvAt23" width="75" height="75" alt="Using MAXQDA for Qualitative Data Analysis on Linux" typeof="foaf:Image" class="img-responsive" /> </a> </div></div><div class="views-field views-field-title"><span class="field-content"><a href="/content/using-maxqda-qualitative-data-analysis-linux" hreflang="en">Using MAXQDA for Qualitative Data Analysis on Linux</a></span></div><div class="views-field views-field-uid"><span class="field-content"><a href="/users/george-whittaker" hreflang="en">George Whittaker</a></span></div></div> <div class="views-row"><div class="views-field views-field-field-node-image"><div class="field-content"> <a href="/content/haproxy-ubuntu-load-balancing-and-failover-resilient-infrastructure" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/75x75_square/public/nodeimage/story/haproxy-on-ubuntu-load-balancing-and-failover-for-resilient-infrastructure.jpg?itok=2rVXWl_c" width="75" height="75" alt="HAProxy on Ubuntu: Load Balancing and Failover for Resilient Infrastructure" typeof="foaf:Image" class="img-responsive" /> </a> </div></div><div class="views-field views-field-title"><span class="field-content"><a href="/content/haproxy-ubuntu-load-balancing-and-failover-resilient-infrastructure" hreflang="en">HAProxy on Ubuntu: Load Balancing and Failover for Resilient Infrastructure</a></span></div><div class="views-field views-field-uid"><span class="field-content"><a href="/users/germansuarez" hreflang="en">german.suarez</a></span></div></div> <div class="views-row"><div class="views-field views-field-field-node-image"><div class="field-content"> <a href="/content/linux-binary-analysis-reverse-engineering-and-vulnerability-discovery" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/75x75_square/public/nodeimage/story/linux-binary-analysis-for-reverse-engineering-and-vulnerability-discovery.jpg?itok=vTlNabrQ" width="75" height="75" alt="Linux Binary Analysis for Reverse Engineering and Vulnerability Discovery" typeof="foaf:Image" class="img-responsive" /> </a> </div></div><div class="views-field views-field-title"><span class="field-content"><a href="/content/linux-binary-analysis-reverse-engineering-and-vulnerability-discovery" hreflang="en">Linux Binary Analysis for Reverse Engineering and Vulnerability Discovery</a></span></div><div class="views-field views-field-uid"><span class="field-content"><a href="/users/george-whittaker" hreflang="en">George Whittaker</a></span></div></div> <div class="views-row"><div class="views-field views-field-field-node-image"><div class="field-content"> <a href="/content/debian-backup-and-recovery-solutions-safeguard-your-data-confidence" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/75x75_square/public/nodeimage/story/debian-backup-and-recovery-solutions-safeguard-your-data-with-confidence.jpg?itok=LhESic3E" width="75" height="75" alt="Debian Backup and Recovery Solutions: Safeguard Your Data with Confidence" typeof="foaf:Image" class="img-responsive" /> </a> </div></div><div class="views-field views-field-title"><span class="field-content"><a href="/content/debian-backup-and-recovery-solutions-safeguard-your-data-confidence" hreflang="en">Debian Backup and Recovery Solutions: Safeguard Your Data with Confidence</a></span></div><div class="views-field views-field-uid"><span class="field-content"><a href="/users/george-whittaker" hreflang="en">George Whittaker</a></span></div></div> <div class="views-row"><div class="views-field views-field-field-node-image"><div class="field-content"> <a href="/content/installing-development-tools-debian-setting-compilers-libraries-and-ides-robust-development" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/75x75_square/public/nodeimage/story/installing-development-tools-on-debian-setting-up-compilers-libraries-and-ides-for-a-robust-development-environment.jpg?itok=Aq209Ota" width="75" height="75" alt="Installing Development Tools on Debian: Setting Up Compilers, Libraries, and IDEs for a Robust Development Environment" typeof="foaf:Image" class="img-responsive" /> </a> </div></div><div class="views-field views-field-title"><span class="field-content"><a href="/content/installing-development-tools-debian-setting-compilers-libraries-and-ides-robust-development" hreflang="en">Installing Development Tools on Debian: Setting Up Compilers, Libraries, and IDEs for a Robust Development Environment</a></span></div><div class="views-field views-field-uid"><span class="field-content"><a href="/users/george-whittaker" hreflang="en">George Whittaker</a></span></div></div> <div class="views-row"><div class="views-field views-field-field-node-image"><div class="field-content"> <a href="/content/building-your-own-ubuntu-personal-cloud-step-step-guide-creating-secure-data-haven" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/75x75_square/public/nodeimage/story/building-your-own-ubuntu-personal-cloud-a-step-by-step-guide-to-creating-a-secure-data-haven.jpg?itok=zYkD9lta" width="75" height="75" alt="Building Your Own Ubuntu Personal Cloud: A Step-by-Step Guide to Creating a Secure Data Haven" typeof="foaf:Image" class="img-responsive" /> </a> </div></div><div class="views-field views-field-title"><span class="field-content"><a href="/content/building-your-own-ubuntu-personal-cloud-step-step-guide-creating-secure-data-haven" hreflang="en">Building Your Own Ubuntu Personal Cloud: A Step-by-Step Guide to Creating a Secure Data Haven</a></span></div><div class="views-field views-field-uid"><span class="field-content"><a href="/users/george-whittaker" hreflang="en">George Whittaker</a></span></div></div> </div> </div> </div> </div> <div class="field field--name-dynamic-block-fieldnode-sponsors field--type-ds field--label-hidden field--item"><div class="views-element-container form-group"><div class="view view-latest-sponsor-block view-id-latest_sponsor_block view-display-id-block_1 js-view-dom-id-82cb78003e8f2eff6491948f32e2b202d0c11beadc60ed83a758685aeb1f2e8c"> <div class="view-header"> </div> <div class="view-content"> <div class="views-row"> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"> </div> </div> </div> </div> </div> </div> </div> </article> </div> </section> </div> </div> <footer class="footer container" role="contentinfo"> <div class="region region-footer"> <section class="views-element-container block block-views block-views-blocknewsletter-promo-block-block-1 clearfix" id="block-views-block-newsletter-promo-block-block-1"> <div class="form-group"><div class="view view-newsletter-promo-block view-id-newsletter_promo_block view-display-id-block_1 js-view-dom-id-6fb343e4dd92d8f29db7c0af596ad6b81130749a15a42469d3ab4387a90f5c10"> <div class="view-content"> <div class="views-row"> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><div class="newsletter-bottom"> <div class="col-md-9 col-sm-12 signup-form">     </div> </div> </div> </div> </div> </div> </section> </div> <div class="footer-blocks col-sm-12"> <div class="col-md-6 col-sm-12 footer-left"> <div class="region region-footer-left"> <section id="block-connectwithusfooter" class="block block-block-content block-block-content5e722bd4-5e08-454b-8507-956089bfa661 clearfix"> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><div class="footer-heading">Connect With Us <span class="social-media sm-a-no-underline"><a href="https://youtube.com/linuxjournalonline" alt="Linux Journal on YouTube" aria-label="YouTube"><i class="fa fa-youtube fa-2x"></i></a><a href="https://www.facebook.com/linuxjournal/" alt="Linux Journal on Facebook" aria-label="Facebook"><i class="fa fa-facebook-f fa-2x"></i><a href="https://twitter.com/linuxjournal" alt="Linux Journal on Twitter" aria-label="Twitter"><i class="fa fa-twitter fa-2x"></i></a></span></div> <p>Linux Journal, representing 25+ years of publication, is the original magazine of the global Open Source community.</p></div> </section> <section id="block-linuxjournal-block-9" class="block block-block-content block-block-content8669793b-e217-4426-a79e-eb3c21ede127 clearfix"> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><div id="copyright">© 2024 Slashdot Media, LLC. All rights reserved.</div> </div> </section> <section id="block-privacyterms" class="block block-block-content block-block-contenta203b8bd-80ef-4982-bf6e-784dd7b44120 clearfix"> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><ul class="menu menu--footer-submenu nav" id="terms-nav"> <li><a href="https://slashdotmedia.com/privacy-statement/" rel="nofollow" target="_blank">PRIVACY POLICY</a></li> <li><a href="https://slashdotmedia.com/terms-of-use/" rel="nofollow" target="_blank">TERMS OF SERVICE</a></li> <li><a href="/sponsors">ADVERTISE</a></li> </ul></div> </section> </div> </div> <div class="col-md-4 col-sm-8 footer-middle"> <div class="region region-footer-middle"> <nav role="navigation" aria-labelledby="block-footermenucolumn2-menu" id="block-footermenucolumn2"> <h2 class="visually-hidden" id="block-footermenucolumn2-menu">Footer Menu Column 2</h2> <ul class="menu menu--footer-menu-column-2 nav"> <li class="first"> <a href="/content/masthead" data-drupal-link-system-path="node/1007727">Masthead</a> </li> <li> <a href="/author" data-drupal-link-system-path="node/1009249">Authors</a> </li> <li class="last"> <a href="/form/contact" data-drupal-link-system-path="webform/contact">Contact Us</a> </li> </ul> </nav> <nav role="navigation" aria-labelledby="block-footermenucolumn3-menu" id="block-footermenucolumn3"> <h2 class="visually-hidden" id="block-footermenucolumn3-menu">Footer Menu Column 3</h2> <ul class="menu menu--footer-menu-column-3 nav"> <li class="first"> <a href="/rss_feeds" data-drupal-link-system-path="node/1000457">RSS Feeds</a> </li> <li class="last"> <a href="/aboutus" data-drupal-link-system-path="node/1000267">About Us</a> </li> </ul> </nav> </div> </div> </div> </footer> </div> </div> <script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","scriptPath":null,"pathPrefix":"","currentPath":"node\/1339316","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"bootstrap":{"forms_has_error_value_toggle":1,"popover_enabled":1,"popover_animation":1,"popover_auto_close":1,"popover_container":"body","popover_content":"","popover_delay":"0","popover_html":0,"popover_placement":"right","popover_selector":"","popover_title":"","popover_trigger":"click"},"linuxjournal":{"disqus":{"origin":"https:\/\/www.linuxjournal.com","prettyUrl":"\/content\/grub-boot-iso","fullUrl":"https:\/\/www.linuxjournal.com\/content\/grub-boot-iso","embedUrl":"https:\/\/linuxjournal.disqus.com\/embed.js","shortname":"linuxjournal"}},"statistics":{"data":{"nid":"1339316"},"url":"\/core\/modules\/statistics\/statistics.php"},"ajaxTrustedUrl":{"\/search\/node":true},"user":{"uid":0,"permissionsHash":"a7b3a803411eb9cbd5d7d374ffb326721ee8274ab5a665df8f38311e3aad858c"}}</script> <script src="/core/assets/vendor/jquery/jquery.min.js?v=3.6.3"></script> <script src="/core/assets/vendor/underscore/underscore-min.js?v=1.13.6"></script> <script src="/core/misc/polyfills/element.matches.js?v=9.5.9"></script> <script src="/core/misc/polyfills/object.assign.js?v=9.5.9"></script> <script src="/core/assets/vendor/once/once.min.js?v=1.0.1"></script> <script src="/core/assets/vendor/jquery-once/jquery.once.min.js?v=9.5.9"></script> <script src="/core/misc/drupalSettingsLoader.js?v=9.5.9"></script> <script src="/core/misc/drupal.js?v=9.5.9"></script> <script src="/core/misc/drupal.init.js?v=9.5.9"></script> <script src="/themes/contrib/bootstrap/js/drupal.bootstrap.js?smwnh4"></script> <script src="/themes/contrib/bootstrap/js/attributes.js?smwnh4"></script> <script src="/themes/contrib/bootstrap/js/theme.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/affix.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/alert.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/button.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/carousel.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/collapse.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/dropdown.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/modal.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/tooltip.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/popover.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/scrollspy.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/tab.js?smwnh4"></script> <script src="/themes/linuxjournal/bootstrap/assets/javascripts/bootstrap/transition.js?smwnh4"></script> <script src="/themes/linuxjournal/js/lj-consentmanager.js?smwnh4"></script> <script src="/modules/contrib/webform/js/webform.behaviors.js?v=9.5.9"></script> <script src="/core/misc/jquery.once.bc.js?v=9.5.9"></script> <script src="/core/misc/states.js?v=9.5.9"></script> <script src="/themes/contrib/bootstrap/js/misc/states.js?smwnh4"></script> <script src="/modules/contrib/webform/js/webform.states.js?v=9.5.9"></script> <script src="/modules/contrib/webform/modules/webform_bootstrap/js/webform_bootstrap.states.js?v=9.5.9"></script> <script src="/themes/contrib/bootstrap/js/popover.js?smwnh4"></script> <script src="/core/modules/statistics/statistics.js?v=9.5.9"></script> <script src="/themes/linuxjournal/js/lj-disqus.js?smwnh4"></script> <script src="/libraries/shariff/shariff.complete.js?v=9.5.9"></script>  <noscript><img src="https://api.b2c.com/api/noscript-448i7exgpyqpr9c144q.gif"></noscript>   <script type="text/javascript"> var _paq = _paq || []; function initPiwik() { _paq.push(['trackPageView']); _paq.push(['enableLinkTracking']); (function() { var u="https://analytics.linuxjournal.com/"; _paq.push(['setTrackerUrl', u+'piwik.php']); _paq.push(['setSiteId', '50']); var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0]; g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'piwik.js'; s.parentNode.insertBefore(g,s); })(); } </script> <noscript><p><img src="https://analytics.linuxjournal.com/piwik.php?idsite=50&rec=1" style="border:0;" alt="" /></p></noscript>  <div class="modal-custom overlay-custom" id="ccpa-modal" style="margin-left: 0; display: none; max-width: 100%; width: 100%"> <div id="modal-content" class="modal-content"> <div class="modal-header" id="ccpa-modal-content-destination"></div> <span class="close" id="modal-close">×</span> </div> </div> </body> </html>

CINXE.COM

GRUB Boot from ISO | Linux Journal