Editing Disk partitioning (section)

== Partitioning schemes ==
=== DOS, Windows, and OS/2 ===
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 assignment|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. (Windows 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]], [[Windows XP|XP]], [[Windows Vista|Vista]], and [[Windows 7]] include a '[[Logical Disk Manager|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 [[Logical Disk Manager#Compatibility problems|incompatible]] with Windows 2000, XP, OS/2, DOS as well as many other operating systems.

=== Unix-like systems ===
On [[Unix]]-based and [[Unix-like]] operating systems such as [[Linux]], [[macOS]], [[BSD]], and [[Solaris (operating system)|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 system]]s can be mounted with different parameters, e.g., [[file system permissions|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 [[BSD disklabel|disklabel]]-based partitioning scheme. However, [[GUID Partition Table]] partitions are referred to as "partition" worldwide.

=== Multi-boot systems ===
{{Main article|Multi-boot}}
[[File:GRUB with ubuntu and windows vista.png|thumb|371x371px|A [[GNU GRUB|GRUB]] startup menu showing [[Ubuntu (operating system)|Ubuntu]] Linux (with three different boot modes) and [[Windows Vista]] options]]
Multi-boot systems are computers where the user can boot into more than one distinct operating system (OS) stored in separate storage devices or in separate partitions of the same storage device. In such systems a menu at [[booting|startup]] gives a choice of which OS to boot/start (and only one OS at a time is loaded).

This is distinct from [[virtual machine|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 ===
{{Main article|GUID Partition Table}}
The '''GUID Partition Table''' ([[globally unique identifier|'''G'''lobally '''U'''nique '''ID'''entifier]]) 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. However, Windows does not support this on BIOS based computers.<ref>{{Cite web|last=windows-driver-content|title=BIOS/MBR-based hard drive partitions|url=https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-biosmbr-based-hard-drive-partitions|access-date=2021-12-06|website=docs.microsoft.com|language=en-us|archive-date=2021-07-25|archive-url=https://web.archive.org/web/20210725015718/https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-biosmbr-based-hard-drive-partitions|url-status=live}}</ref>