{"id":5015,"date":"2026-04-04T02:42:05","date_gmt":"2026-04-04T00:42:05","guid":{"rendered":"https:\/\/reparationmac.be\/?p=5015"},"modified":"2026-04-05T13:12:42","modified_gmt":"2026-04-05T11:12:42","slug":"partition-mac-disk-guide","status":"publish","type":"post","link":"https:\/\/reparationmac.be\/en\/partition-disque-mac-guide\/","title":{"rendered":"Disk partitioning: a practical guide"},"content":{"rendered":"<div class=\"article-blog\">\n\n<h1>Partitioning a disk on the Mac: a complete guide to creating and managing partitions<\/h1>\n\n<div class=\"article-meta\">Reading: 12 min | macOS Tutorials<\/div>\n\n<img fetchpriority=\"high\" decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/04\/partition-disque-mac-guide.webp\" alt=\"Partitioning a disk on a Mac with Disk Utility\" title=\"Complete guide to partitioning a disk on a Mac\" width=\"1200\" height=\"568\" loading=\"eager\">\n\n<div class=\"answer-box\">\nTo sum up: to partition a disk on a Mac, open Disk Utility (Applications \u2192 Utilities), select your disk, click on \u00abPartition\u00bb and add the volumes you want. On recent Macs with APFS, prefer APFS volumes to traditional partitions - they share space dynamically with no fixed limit, which is more flexible and safer.\n<\/div>\n\n<div class=\"toc-box\">\n<strong>Contents<\/strong>\n<ul>\n<li><a href=\"#pourquoi-partitionner\">Why partition a Mac disk<\/a><\/li>\n<li><a href=\"#apfs-vs-partition\">APFS volumes or traditional partitions: what's the difference?<\/a><\/li>\n<li><a href=\"#creer-volume-apfs\">Create an APFS volume (recommended method)<\/a><\/li>\n<li><a href=\"#creer-partition\">Creating a classical score<\/a><\/li>\n<li><a href=\"#partition-terminal\">Partition via Terminal<\/a><\/li>\n<li><a href=\"#cas-pratiques\">Practical examples: when and how to partition<\/a><\/li>\n<li><a href=\"#supprimer-partition\">Delete a partition or volume<\/a><\/li>\n<li><a href=\"#faq\">Frequently asked questions<\/a><\/li>\n<\/ul>\n<\/div>\n\n<h2 id=\"pourquoi-partitionner\">Why partition a Mac disk<\/h2>\n\n<p>Partitioning a disk consists of dividing it into several independent sections, each behaving as a separate disk in the eyes of macOS. There are several situations in which this operation is justified: installing a second operating system (Windows via Boot Camp on Intel Macs, or an older version of macOS to test compatibility), separating personal data from the system to facilitate reinstallations, creating a volume dedicated to Time Machine backup on a large external drive, or isolating a development environment.<\/p>\n\n<p>Before you get started, it's essential to understand the difference between APFS volumes and conventional partitions, because macOS offers both approaches - and the right choice depends on your situation.<\/p>\n\n<h2 id=\"apfs-vs-partition\">APFS volumes or traditional partitions: what's the difference?<\/h2>\n\n<p>Since macOS High Sierra (2017), Apple has been using the APFS (Apple File System) file system by default on all SSD-equipped Macs. This modern file system fundamentally changes the way we manage disk space.<\/p>\n\n<table class=\"tg-table\">\n<thead>\n<tr>\n<th>Criteria<\/th>\n<th>Classical score<\/th>\n<th>APFS volume<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><span class=\"cell-label\">Space allocation<\/span><\/td>\n<td><span class=\"cell-desc\">Fixed - size defined at inception<\/span><\/td>\n<td><span class=\"cell-desc\">Dynamic - automatically shared space<\/span><\/td>\n<\/tr>\n<tr>\n<td><span class=\"cell-label\">Resize<\/span><\/td>\n<td><span class=\"cell-desc\">Requires a dedicated operation (risk of data loss)<\/span><\/td>\n<td><span class=\"cell-desc\">Automatic, without intervention<\/span><\/td>\n<\/tr>\n<tr>\n<td><span class=\"cell-label\">Creation speed<\/span><\/td>\n<td><span class=\"cell-desc\">Several minutes (data movement)<\/span><\/td>\n<td><span class=\"cell-desc\">Almost instantaneous<\/span><\/td>\n<\/tr>\n<tr>\n<td><span class=\"cell-label\">File system<\/span><\/td>\n<td><span class=\"cell-desc\">APFS, Mac OS extended (HFS+), ExFAT, FAT32<\/span><\/td>\n<td><span class=\"cell-desc\">APFS only<\/span><\/td>\n<\/tr>\n<tr>\n<td><span class=\"cell-label\">Ideal use case<\/span><\/td>\n<td><span class=\"cell-desc\">Boot Camp (Windows), multi-OS external drives<\/span><\/td>\n<td><span class=\"cell-desc\">Data separation, multi-macOS, development<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n<div class=\"info-box tip\">\n<strong>Technical advice :<\/strong> In the vast majority of cases, an APFS volume is preferable to a conventional partition. Space is shared dynamically between volumes, which avoids the classic problem of one partition being \u00abfull\u00bb while the other has free space. Only create a conventional partition if you have a specific need (Boot Camp, ExFAT format for Windows\/Mac compatibility).\n<\/div>\n\n<h2 id=\"creer-volume-apfs\">Create an APFS volume (recommended method)<\/h2>\n\n<p>Creating an APFS volume is the modern and recommended way to separate your data on a recent Mac. The operation is fast, reversible and without risk to your existing data.<\/p>\n\n<h3>Step-by-step procedure<\/h3>\n\n<ol>\n<li>Open the\u2019<strong>Disk utility<\/strong> (Applications \u2192 Utilities \u2192 Disk Utility, or via Spotlight with Cmd + Space).<\/li>\n<li>In the sidebar, make sure that the display is set to <strong>\u00abDisplay all devices\u00bb<\/strong> (Presentation menu).<\/li>\n<li>Select the <strong>APFS container<\/strong> (usually called \u00abContainer diskX\u00bb) which contains your macOS volume.<\/li>\n<li>Click on the <strong>\u00ab\u00a0+\u00a0\u00bb<\/strong> in the toolbar, or go to Edit \u2192 Add an APFS volume.<\/li>\n<li>Give a <strong>name<\/strong> to your new volume (e.g. \u00abData\u00bb, \u00abProjects\u00bb or \u00abDevelopment\u00bb).<\/li>\n<li>Choose the <strong>format<\/strong> APFS (standard), encrypted APFS (recommended for sensitive data), case-sensitive APFS, or case-sensitive and encrypted APFS.<\/li>\n<li>Optional: click on <strong>\u00abSize options\u00bb<\/strong> to define a reserve size (minimum guaranteed) and a quota (maximum authorised).<\/li>\n<li>Click on <strong>\u00abAdd\u00bb<\/strong>. The volume is created in a matter of seconds.<\/li>\n<\/ol>\n\n<p>The new volume appears immediately in the Finder, in the sidebar under \u00abLocations\u00bb. You can access it just like any other disk. For more advanced use of the Disk Utility, see our <a href=\"\/en\/mac-disk-utility-guide\/\">complete guide to Mac Disk Utility<\/a>.<\/p>\n\n<img decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/04\/creer-volume-apfs-utilitaire-disque-mac.webp\" alt=\"Creating an APFS volume in Disk Utility on the Mac\" title=\"Create an APFS volume on a Mac with Disk Utility\" width=\"1200\" height=\"568\" loading=\"lazy\">\n\n<div class=\"info-box warning\">\n<strong>Important information:<\/strong> if you choose the encrypted APFS format, make a careful note of the password. Without this password, the data on the volume will be permanently inaccessible. For a complete data protection strategy, see our guide <a href=\"\/en\/protect-mac-data-security\/\">protect your data on the Mac<\/a>.\n<\/div>\n\n<h2 id=\"creer-partition\">Creating a classical score<\/h2>\n\n<p>Creating a classic partition is necessary in certain specific cases: installing Windows via Boot Camp (Intel Macs only), formatting a section of external disk in ExFAT for mixed Mac\/Windows use, or maintaining compatibility with older systems.<\/p>\n\n<h3>Disk Utility procedure<\/h3>\n\n<ol>\n<li>Open the\u2019<strong>Disk utility<\/strong> and activate <strong>\u00abDisplay all devices\u00bb<\/strong>.<\/li>\n<li>Select the <strong>physical disk<\/strong> (not a volume or container, but the root device in the tree).<\/li>\n<li>Click on <strong>\u00abPartitioning\u00bb<\/strong> in the toolbar.<\/li>\n<li>macOS displays a pie chart showing the current disk space. Click on the <strong>\u00ab\u00a0+\u00a0\u00bb<\/strong> to add a partition.<\/li>\n<li>Define the <strong>size<\/strong> of the new partition by dragging the separator or entering a value.<\/li>\n<li>Choose the <strong>format<\/strong> APFS, Mac OS Extended (journalled), ExFAT or MS-DOS (FAT).<\/li>\n<li>Give a <strong>name<\/strong> to the score.<\/li>\n<li>Click on <strong>\u00abApply\u00bb<\/strong>. The operation may take several minutes, depending on the size of the data to be moved.<\/li>\n<\/ol>\n\n<div class=\"info-box danger\">\n<strong>Review:<\/strong> Partitioning a disk containing data involves a risk of data loss, even if Disk Utility is designed to be non-destructive. Always make a full backup via <a href=\"\/en\/time-machine-mac-backup\/\">Time Machine<\/a> before any partitioning operation. If anything goes wrong, a backup will be your only recourse.\n<\/div>\n\n<h2 id=\"partition-terminal\">Partition via Terminal<\/h2>\n\n<p>Terminal offers granular control over partitioning via the command <code>diskutil<\/code>. This approach is reserved for advanced users who need precision or automation. To familiarise yourself with the Terminal, our guide to <a href=\"\/en\/mac-terminal-useful-commands\/\">Mac Terminal commands<\/a> covers the essential basics.<\/p>\n\n<h3>Create an APFS volume using Terminal<\/h3>\n\n<p><code>diskutil apfs addVolume diskX APFS \"VolumeName\"<\/code><\/p>\n\n<p>Replace <code>diskX<\/code> by the identifier of your APFS container (visible with <code>diskutil list<\/code>) and \u00abVolumeName\u00bb by the desired name.<\/p>\n\n<h3>Create an encrypted APFS volume<\/h3>\n\n<p><code>diskutil apfs addVolume diskX \"APFS (Encrypted)\" \"VolumeName\" -passphrase \"YourPassword\"<\/code><\/p>\n\n<h3>List all disks and volumes<\/h3>\n\n<p><code>diskutil list<\/code><\/p>\n\n<p>This command displays the complete tree structure of all the disks, containers, volumes and partitions on your Mac. It's the essential starting point before any manipulation.<\/p>\n\n<h3>Creating a classical score<\/h3>\n\n<p><code>diskutil partitionDisk diskX GPT APFS \"Volume1\" 50% ExFAT \"Volume2\" 50%<\/code><\/p>\n\n<div class=\"info-box danger\">\n<strong>Please note:<\/strong> the order <code>partitionDisk<\/code> erases the entire target disk before creating new partitions. Use it only on an empty disk or one where you have backed up all the data. To add a partition without erasing, use <code>diskutil splitPartition<\/code>.\n<\/div>\n\n<h2 id=\"cas-pratiques\">Practical examples: when and how to partition<\/h2>\n\n<h3>Installing Windows on Mac Intel (Boot Camp)<\/h3>\n\n<p>The Boot Camp Wizard automatically creates a partition dedicated to Windows on your internal disk. You don't need to use Disk Utility - the Wizard takes care of everything: partitioning, NTFS formatting and installing Apple drivers. Allow at least 64 GB for Windows, ideally 128 GB if you plan to install applications. Our guide <a href=\"\/en\/dual-boot-mac-windows-boot-camp\/\">dual boot Mac Windows<\/a> details the full procedure.<\/p>\n\n<h3>Multi-purpose external disk (Mac and Windows)<\/h3>\n\n<p>If you share an external drive between a Mac and a Windows PC, the ExFAT format is the best compromise: readable and writable natively by both systems. You can also partition the drive in two: an APFS partition for Time Machine and an ExFAT partition for file exchange.<\/p>\n\n<h3>Testing a beta version of macOS<\/h3>\n\n<p>Create a separate APFS volume and install the macOS beta on it. At boot time, hold down the Option (Alt) key to choose which volume to boot from. This approach protects your main installation from any problems related to the beta. Once the testing period is over, simply delete the volume - the space is freed up instantly.<\/p>\n\n<h3>Separate system and data<\/h3>\n\n<p>Since macOS Catalina, Apple has already separated the system (read-only volume) and user data into two separate APFS volumes. Creating a third volume for your projects or work files can make it easier to reinstall macOS without affecting your personal data.<\/p>\n\n<img decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/04\/cas-pratiques-partition-mac-schemas.webp\" alt=\"Case studies for partitioning a Mac disk\" title=\"Practical examples of partitioning on the Mac\" width=\"1200\" height=\"568\" loading=\"lazy\">\n\n<h2 id=\"supprimer-partition\">Delete a partition or volume<\/h2>\n\n<h3>Delete an APFS volume<\/h3>\n\n<ol>\n<li>Open the\u2019<strong>Disk utility<\/strong>.<\/li>\n<li>Select the APFS volume to be deleted in the sidebar.<\/li>\n<li>Click on the <strong>\u00ab\u00a0\u2013\u00a0\u00bb<\/strong> in the toolbar, or Edit \u2192 Delete APFS volume.<\/li>\n<li>Confirm the deletion. The space is immediately reclaimed by the container.<\/li>\n<\/ol>\n\n<h3>Deleting a classic score<\/h3>\n\n<ol>\n<li>Open the\u2019<strong>Disk utility<\/strong> and select the <strong>physical disk<\/strong>.<\/li>\n<li>Click on <strong>\u00abPartitioning\u00bb<\/strong>.<\/li>\n<li>In the pie chart, select the partition to be deleted and click on <strong>\u00ab\u00a0\u2013\u00a0\u00bb<\/strong>.<\/li>\n<li>Click on <strong>\u00abApply\u00bb<\/strong>. The space is reallocated to the adjacent partition.<\/li>\n<\/ol>\n\n<div class=\"info-box warning\">\n<strong>Please note:<\/strong> deleting a partition or volume deletes all the data it contains. Make sure you have backed up everything you need before proceeding. This operation cannot be reversed.\n<\/div>\n\n<p>To help you manage your disks further, Apple provides comprehensive documentation on the <a href=\"https:\/\/support.apple.com\/fr-be\/guide\/disk-utility\/dskutl14027\/mac\" rel=\"noopener\" target=\"_blank\">partitioning with Disk Utility<\/a>.<\/p>\n\n<h2 id=\"faq\">Frequently asked questions<\/h2>\n\n<div class=\"faq-section\">\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>Does partitioning a disk erase data?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>Adding an APFS volume doesn't delete any existing data - it's a non-destructive and almost instantaneous operation. Adding a conventional partition should not erase any data either, but there is a risk when resizing. The Terminal command <code>partitionDisk<\/code> erases the entire disk. In all cases, make a backup beforehand.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>What is the difference between an APFS volume and a partition?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>A partition physically divides the disk into sections of fixed size. An APFS volume is a logical subdivision within an APFS container, with space shared dynamically. APFS volumes are more flexible: they grow and shrink automatically as needed, without wasting space.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>Is it possible to partition the internal drive of an Apple Silicon Mac?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>Yes, you can add APFS volumes to the main container. However, creating conventional partitions on the internal disk of an Apple Silicon Mac is limited by the system's security mechanisms (Signed System Volume). The recommended method is to add APFS volumes.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>What format should I choose for an external drive used on a Mac or PC?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>ExFAT is the best choice: it can be read and written natively by macOS, Windows and most devices (TV, consoles). It does not have the 4GB limit per file of the FAT32 format. For a Mac-only drive, APFS is optimal.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>How do I resize an existing partition?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>In the Disk Utility, select the physical disk, click Partition, then drag the separator into the pie chart. Resizing is only possible if there is enough free space and the data is not blocking the operation. APFS volumes resize automatically.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>Can I install two versions of macOS on the same Mac?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>Yes. Create an additional APFS volume and install the second version of macOS on it. At boot time, hold down the Option (Alt) key to choose the boot volume. This is the recommended method for testing beta versions without risking your main installation.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>The \u00abPartition\u00bb button is greyed out. What should I do?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>There are several possible causes: you have selected a volume instead of the physical disk (activate \u00abShow all devices\u00bb), the disk is being used by Time Machine or another process, or the disk partition scheme is not compatible (GUID required). If the problem persists, our team can help you with a <a href=\"\/en\/free-mac-diagnostic\/\">free diagnosis<\/a>.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>Is Boot Camp available on Apple Silicon Macs?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>No. Boot Camp is not available on Macs equipped with Apple Silicon chips (M1 and later). To run Windows on these machines, you need to use virtualisation software such as Parallels Desktop or UTM, which work without partitioning - Windows runs in a window inside macOS.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>Should I partition an external SSD for Time Machine?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>If your external drive is large enough (at least twice the size of your internal drive), you can create an APFS volume dedicated to Time Machine and use the rest for regular storage. macOS manages this configuration very well. See our <a href=\"\/en\/time-machine-mac-backup\/\">Time Machine guide<\/a> for the installation.<\/p><\/div>\n<\/div>\n\n<div class=\"faq-item\">\n<div class=\"faq-question\"><span>Can MAC Repair help me partition my disk?<\/span><span class=\"faq-toggle\">+<\/span><\/div>\n<div class=\"faq-answer\"><p>Of course you can. With over 15 years' experience since 2010, our team carries out partitioning, multi-boot configuration and data migration between volumes. We ensure that your data is backed up before any manipulation and check the integrity of the disk after the operation. 180-day guarantee on all our services.<\/p><\/div>\n<\/div>\n\n<\/div>\n\n<div class=\"related-links\">\n<strong>Related articles<\/strong>\n<ul>\n<li><a href=\"\/en\/mac-disk-utility-guide\/\">Mac Disk Utility: complete guide<\/a><\/li>\n<li><a href=\"\/en\/dual-boot-mac-windows-boot-camp\/\">Dual boot Mac Windows: installing Windows on a Mac<\/a><\/li>\n<li><a href=\"\/en\/choose-install-mac-ssd-guide\/\">Mac SSD upgrade: complete guide<\/a><\/li>\n<li><a href=\"\/en\/time-machine-mac-backup\/\">Configuring Time Machine: complete guide<\/a><\/li>\n<\/ul>\n<\/div>\n\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Partitionner un disque sur Mac : guide complet pour cr\u00e9er et g\u00e9rer vos partitions Lecture : 12 min | Tutoriels macOS En r\u00e9sum\u00e9 : pour partitionner un disque sur Mac, ouvrez l&rsquo;Utilitaire de disque (Applications \u2192 Utilitaires), s\u00e9lectionnez votre disque, cliquez sur \u00ab\u00a0Partitionner\u00a0\u00bb et ajoutez les volumes souhait\u00e9s. Sur les Mac r\u00e9cents avec APFS, privil\u00e9giez [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":5018,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_breakdance_hide_in_design_set":false,"_breakdance_tags":"","footnotes":""},"categories":[13],"tags":[208,289,154,292,215,290,259,183,119,291],"class_list":["post-5015","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tutoriels-macos","tag-boot-camp","tag-disque-externe-mac","tag-exfat","tag-multi-boot-mac","tag-partition-mac","tag-partitionner-disque","tag-ssd-mac","tag-terminal-mac-2","tag-utilitaire-de-disque","tag-volume-apfs"],"_links":{"self":[{"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/posts\/5015","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/comments?post=5015"}],"version-history":[{"count":0,"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/posts\/5015\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/media\/5018"}],"wp:attachment":[{"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/media?parent=5015"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/categories?post=5015"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/reparationmac.be\/en\/wp-json\/wp\/v2\/tags?post=5015"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}