According to a Lifehacker how-to, it is possible to dual-boot an Intel-based Mac with OSX and GNU-Linux, but you'll need to shrink your HFS partition and create an EXT3/4 partition and a swap partition in that space (instead of installing in/on an HFS partition).The following is verbatim from that How-To. Boot your Mac into OS X. If you're lucky, this may be one of the last times you have to. Step 5: The wizard will ask you to select set partition size, drive letter, file system, format method, etc. You can follow suggested option to complete the process. Method 3: Format external hard drive for Mac and PC. Want to use external hard drive under both Windows PC and Mac?

Disk partitioning or disk slicing^[1] is the creation of one or more regions on secondary storage, so that each region can be managed separately.^[2] These regions are called partitions. It is typically the first step of preparing a newly installed disk, before any file system is created. The disk stores the information about the partitions' locations and sizes in an area known as the partition table that the operating system reads before any other part of the disk. Each partition then appears to the operating system as a distinct 'logical' disk that uses part of the actual disk. System administrators use a program called a partition editor to create, resize, delete, and manipulate the partitions.^[3] Partitioning allows the use of different filesystems to be installed for different kinds of files. Separating user data from system data can prevent the system partition from becoming full and rendering the system unusable. Partitioning can also make backing up easier. A disadvantage is that it can be difficult to properly size partitions, resulting in having one partition with much free space and another nearly totally allocated.

PC partition types[edit]

This section describes the master boot record (MBR) partitioning scheme, as used historically in DOS, Microsoft Windows and Linux (among others) on PC-compatible computer systems. As of the mid-2010s, most new computers use the GUID Partition Table (GPT) partitioning scheme instead. For examples of other partitioning schemes, see the general article on partition tables.

The total data storage space of a PC HDD on which MBR partitioning is implemented can contain at most four primary partitions, or alternatively three primary partitions and an extended partition. The Partition Table, located in the master boot record, contains 16-byte entries, each of which describes a partition.

The partition type is identified by a 1-byte code found in its partition table entry. Some of these codes (such as 0x05 and 0x0F) may be used to indicate the presence of an extended partition. Most are used by an operating system's bootloader (that examines partition tables) to decide if a partition contains a file system that can be mounted / accessed for reading or writing data.

Primary partition[edit]

A primary partition contains one file system. In DOS and all early versions of Microsoft Windows systems, Microsoft required what it called the system partition to be the first partition. All Windows operating systems from Windows 95 onwards can be located on (almost) any partition, but the boot files (io.sys, bootmgr, ntldr, etc.) must reside on a primary partition. However, other factors, such as a PC's BIOS (see Boot sequence on standard PC) may also impose specific requirements as to which partition must contain the primary OS.

The partition type code for a primary partition can either correspond to a file system contained within (e.g., 0x07 means either an NTFS or an OS/2 HPFS file system) or indicate that the partition has a special use (e.g., code 0x82 usually indicates a Linux swap partition). The FAT16 and FAT32 file systems have made use of a number of partition type codes due to the limits of various DOS and Windows OS versions. Though a Linux operating system may recognize a number of different file systems (ext4, ext3, ext2, ReiserFS, etc.), they have all consistently used the same partition type code: 0x83 (Linux native file system).

Extended partition[edit]

An HDD may contain only one extended partition, but that extended partition can be subdivided into multiple logical partitions. DOS/Windows systems may then assign a unique drive letter to each logical partition.

Partitioning schemes[edit]

DOS, Windows, and OS/2[edit]

Linux Disk Partitioning

With DOS, Microsoft Windows, and OS/2, a common practice is to use one primary partition for the active file system that will contain the operating system, the page/swap file, all utilities, applications, and user data. On most Windows consumer computers, the drive letter C: is routinely assigned to this primary partition. Other partitions may exist on the HDD that may or may not be visible as drives, such as recovery partitions or partitions with diagnostic tools or data. (Microsoft drive letters do not correspond to partitions in a one-to-one fashion, so there may be more or fewer drive letters than partitions.)

Microsoft Windows 2000, XP, Vista, and Windows 7 include a 'Disk Management' program which allows for the creation, deletion and resizing of FAT and NTFS partitions. The Windows Disk Manager in Windows Vista and Windows 7 utilizes a 1 MB partition alignment scheme which is fundamentally incompatible with Windows 2000, XP, OS/2, DOS as well as many other operating systems.

Unix-like systems[edit]

On Unix-based and Unix-like operating systems such as Linux, macOS, BSD, and Solaris, it is possible to use multiple partitions on a disk device. Each partition can be formatted with a file system or as a swap partition.

Multiple partitions allow directories such as /boot, /tmp, /usr, /var, or /home to be allocated their own filesystems. Such a scheme has a number of advantages:

• If one file system gets corrupted, the data outside that filesystem/partition may stay intact, minimizing data loss.
• Specific file systems can be mounted with different parameters, e.g., read-only, or with the execution of setuid files disabled.
• A runaway program that uses up all available space on a non-system filesystem does not fill up critical filesystems.
• Keeping user data such as documents separate from system files allows the system to be updated with lessened risk of disturbing the data.

A common minimal configuration for Linux systems is to use three partitions: one holding the system files mounted on '/' (the root directory), one holding user configuration files and data mounted on /home (home directory), and a swap partition.

By default, macOS systems also use a single partition for the entire filesystem and use a swap file inside the file system (like Windows) rather than a swap partition.

In Solaris, partitions are sometimes known as slices. This is a conceptual reference to the slicing of a cake into several pieces.

The term 'slice' is used in the FreeBSD operating system to refer to Master Boot Record partitions, to avoid confusion with FreeBSD's own disklabel-based partitioning scheme. However, GUID Partition Table partitions are referred to as 'partition' worldwide.

Multi-boot and mixed-boot systems^{[clarification needed]}[edit]

Multi-boot systems are computers where the user can boot into one of two or more distinct operating systems (OS) stored in separate storage devices or in separate partitions of the same storage device. In such systems a menu at startup gives a choice of which OS to boot/start (and only one OS at a time is loaded).

This is distinct from virtual operating systems, in which one operating system is run as a self-contained virtual 'program' within another already-running operating system. (An example is a Windows OS 'virtual machine' running from within a Linux OS.)

GUID Partition Table[edit]

The GUID Partition Table (Globally Unique IDentifier) is a part of the Unified Extensible Firmware Interface (UEFI) standard for the layout of the partition table on a physical hard disk. Many operating systems now support this standard.

Partition recovery[edit]

When a partition is deleted, its entry is removed from a table and the data is no longer accessible. The data remains on the disk until being overwritten. Specialized recovery utilities may be able to locate lost file systems and recreate a partition table which includes entries for these recovered file systems. Some disk utilities may overwrite a number of beginning sectors of a partition they delete. For example, if Windows Disk Management (Windows 2000/XP, etc.) is used to delete a partition, it will overwrite the first sector (relative sector 0) of the partition before removing it. It still may be possible to restore a FAT or NTFS partition if a backup boot sector is available.

Compressed disks[edit]

HDDs can be compressed to create additional space. In DOS and early Microsoft Windows, programs such as Stacker (DR-DOS except 6.0), SuperStor (DR DOS 6.0), DoubleSpace (MS-DOS 6.0–6.2), or DriveSpace (MS-DOS 6.22, Windows 9x) were used. This compression was done by creating a very large file on the partition, then storing the disk's data in this file. At startup, device drivers opened this file and assigned it a separate letter. Frequently, to avoid confusion, the original partition and the compressed drive had their letters swapped, so that the compressed disk is C:, and the uncompressed area (often containing system files) is given a higher name.

Versions of Windows using the NT kernel, including the most recent version, Windows 10, contain intrinsic disk compression capability. The use of separate disk compression utilities has declined sharply.

See also[edit]

• Extended boot record covers a Linux partition naming convention
• Master boot record covers the partition table layout

References[edit]

1. ^Calkins, Bill (2013). Oracle Solaris 11 System Administration.
2. ^Levi, Bozidar (2002). UNIX Administration.
3. ^Ward, Brian (2004). How Linux Works: What Every SuperUser Should Know. No Starch Press. p. 39. ISBN9781593270353.

Further reading[edit]

• Stéphane Martineau; Jens Olsson; Nick Roberts (2002-11-02). 'The Alt-OS-Development Partition Specification (AODPS)'. 0.4. Archived from the original on 2004-02-13.CS1 maint: unfit url (link)
• Andries Brouwer (1995–2004). 'List of partition identifiers for PCs'.
• Andries Brouwer (1999-09-16). 'Minimal Partition Table Specification'.
• 'partitioning primer'. Ranish. 1998-08-05. Archived from the original on 2004-08-04. Retrieved 2004-08-15.
• Allen Smith. 'ATA (EIDE) Drive Capacity and Addressing'.
• Microsoft (2005-06-03). 'Using GPT Drives'. Archived from the original on 2005-07-06.
• 'MS-DOS Partitioning Summary'. Support. Microsoft.

External links[edit]

• Partition Definition – by The Linux Information Project (LINFO)
• Multiple OS Installation in multiple partitions – guide to using chainloaded bootloaders to enable multiple OSs to coexist
• Partition Tables – a list of partition tables file system codes

Linux is an open-source operating system that you can install on your computer for free. It offers several advantages over Windows and Mac, such as flexibility, privacy, better security, and easy customization. If you have a Mac, and you would like to explore a new, open-source OS, check out our guide on how to install Linux on a Mac.

If you want to dualboot Linux and macOS, you will need to create a space for your Linux OS tolive. In order to do this, you will have to partition your main hard drive.Here’s how to do that:

How to Partition yourMac Hard Drive

1. Open your Applications folder and click Utilities.
2. Then open Disk Utility.
3. Next, click View in the top left corner of the window.
4. Then select Show All Devices.
5. Select your macOS partition and then click Partition. You can find this button at the top of the window. If you are using a newer Mac, you might be asked to add a volume. You can click Partition on the pop-up.
6. Set the partition size you need for your Linux OS. You can do this by dragging the little white circles on the edge of the larger circle, or you can enter the size in the box next to Size. The gray side of the pie will be your Mac space, while the blue space will be your new partition. It is recommended that you set aside at least 20GB for Linux. You can also add other information here as well, such as the partition name. Take note of the size of your partition, you will need this information later.
7. Format the new partition as MS-DOS (FAT).
8. Click Apply. This will cause your computer to become unresponsive as the partition is created.
9. Click Partition and Continue when further prompted and wait for the partition process to finish.

How to Make a BootableUSB on a Mac

1. Download a Linux distro. An ISO file is a disk image. Some of the top options are Ubuntu, Mint, or Deepin. They are free to download from each distribution’s main website. In this article, we are using Ubuntu.
2. Open Disk Utility, select your USB drive, and click Erase.
3. Then format your USB drive as MS-DOS (FAT) and the scheme as GUID Partition Map. You can do this in Disk Utility by selecting your drive and clicking Erase.
4. Download the Etcher app. This will allow you to burn your Linux distro onto a USB flash drive. You can download Etcher for free here.
5. Move the Etcher app to your Applications folder. If you get a warning saying that you are not able to open the application, you will have to go to System Preferences > Security and Privacy > General. Then click the lock, enter your password, and click Open Anyway.
6. Open Etcher, click Select Image, and select your Linux ISO. This is the file you downloaded in step one.
7. Click Select target and choose your USB drive.
8. Then click Flash. If you get an error message, and you’re running a newer OS, go to Applications > Utilities and open the Terminal app. Then enter the following command and hit enter:

If you still get an error message that says thedisk you inserted was not readable, click ignore.

How to Install Linux on a Mac

Once you’ve made a partition, you can thencontinue with the rest of the Linux installation setup below. But beforeyou begin, you will need a USB mouse and keyboard. This is because Linux willnot detect your drivers if you have a newer Mac.

1. Switch off your Mac computer.
2. Plug the bootable Linux USB drive into your Mac.
3. Turn on your Mac while holding down the Option key. You will then see the boot manager with a list of available devices you can boot from.
4. Select your USB stick and hit enter. This will be named EFI boot or EFI drive.
5. Then select Install from the GRUB menu. You can also select Try Without Installing.
6. Follow the on-screen installation instructions. Select Normal Installation.
7. On the Installation Type window, choose Something else. This is an option that will let you choose the partition you made earlier for installing your new Linux OS. If you choose the other options, you risk installing Linux over your current operating system, which would also erase all your files and folders.
8. Choose the partition you made. This is the partition that is the same size as the one that you made earlier.
9. Then click Change. You will see this under the list of devices.
10. In the Use as drop-down, select ext4 journaling file system.
11. In the Mount Point drop-down, select forward slash and click OK.
12. Click Continue when prompted.
13. Then click Install Now.
14. Next, click Continue on succeeding warning pop-ups.
15. Enter your time zone, choose your keyboard layout, and click Continue.
16. Set up your Linux account. Type in your name, computer name, username, and password.
17. Click Continue.
18. Wait for the installation process to start and finish.
19. Restart your Mac and hold down the Option key while it does.
20. Choose your Linux OS to start using it.

After installing the OS and exploring it, makesure that your applications are working properly.

Now that you know how to install Linux on your Mac, check out our guide on how to install Linux on a Windows 10 computer.

Linux Partitioning Best Practice