Disk partitioning

A computer disk can be split into parts.

These parts are called partitions. Each part works on its own. This helps keep your files safe. One part can hold the system. Another part can hold your files.

This keeps things neat. If one part breaks, your other files stay safe. It is like a cake with slices. You can even have two different systems on one disk. This lets you choose which one to use at the start.

A computer disk can be split into parts.

These parts are called partitions. Each partition acts like its own separate disk. This is done by creating regions on a storage device. To manage this, the computer uses a partition table. This table is a list that shows where each part is. It also shows how big each part is. The computer reads this table before doing anything else.

Why do we use partitions? One way is to keep things organized. You can put the system files on one part. You can put your own files on another part. This helps if a program uses too much space. It will not fill up the whole disk. It also helps keep data safe. If one part has a problem, the other parts might stay okay.

You can even use more than one system. This is called a multi-boot system. A menu appears when you start the computer. You can choose which system to use. Some people use a tool called a partition editor. This tool lets you make, change, or delete parts.

Disk partitioning is a way to divide a single storage device into several separate regions. These regions are called partitions. Each partition acts like its own distinct logical disk to the computer. This is a very important step when setting up a brand new disk. Before any files can be saved, a partitioning scheme must be chosen. The disk uses a partition table to keep track of everything. This table stores the exact locations and sizes of every partition. The operating system reads this table before it does anything else.

Partitioning works by creating these separate areas to manage data differently. You can use different file systems for different kinds of files. One big benefit is keeping your personal data away from system data. If a system partition gets completely full, the computer might stop working. By using a separate partition for your files, this problem is avoided. Partitioning also makes it much easier to back up your important information. It can be hard to decide how big each part should be. If one part is too small, it might run out of room. If another is too large, it might waste space.

People have been using these methods for a very long time. In 1966, IBM used a version of this called a minidisk. This was part of their CP-67 operating system. Later, Data General used the word partition for their Nova computers. These partitions each had their own special directory. In 1983, IBM released PC DOS version 2.0. This version used the term partition to describe dividing a storage device. Today, the word is used everywhere in the world of computers.

Different types of computers use different rules for their partitions. On Windows computers, the main partition is often called the C: drive. Windows 2000 and newer versions include a tool called Disk Management. This tool lets you create or resize FAT and NTFS partitions. Unix-like systems like Linux or macOS also use multiple partitions. A common Linux setup uses three parts: a root directory, a home directory, and a swap partition. Some systems, like Solaris, even call these partitions slices. This is like slicing a cake into several pieces.

You can even use one computer to run more than one operating system. This is called a multi-boot system. When you start the computer, a menu appears on the screen. You can then choose which system you want to use. This is different from a virtual machine, which runs inside another system. Most new computers now use the GUID Partition Table, or GPT. This is part of a standard called UEFI. Older systems often used the Master Boot Record, or MBR, scheme.

Disk partitioning is the process of dividing a single physical storage device into multiple distinct regions. These regions are known as partitions. Each partition functions as a separate logical disk to the operating system. This process is usually the first step in preparing a newly installed disk. Before any file system can be created, a specific partitioning scheme must be selected. The disk maintains a partition table to track these regions. This table stores the exact locations and sizes of every partition. The operating system reads this table before performing any other tasks on the disk.

To manage these regions, system administrators use specialized software called a partition editor. These tools allow users to create, resize, delete, and manipulate partitions. One primary reason for partitioning is the ability to use different file systems for different tasks. For example, you can separate user data from critical system data. This separation prevents the system partition from becoming completely full. If a system partition fills up, it can render the entire operating system unusable. Partitioning also simplifies the process of backing up specific sets of data. However, choosing the correct size for each partition can be difficult. Improper sizing might leave one partition with too much empty space while another is nearly full.

Different operating systems utilize various partitioning schemes and naming conventions. In Microsoft Windows environments, the primary partition often contains the operating system and applications. This partition is frequently assigned the drive letter C:. Windows 2000 and later versions include a tool called Disk Management. This program allows users to create, delete, and resize FAT and NTFS partitions. Windows Vista and Windows 7 use a 1 MB partition alignment scheme. This specific alignment is fundamentally incompatible with older systems like Windows 2000, XP, or DOS.

Unix-like systems, such as Linux, macOS, and Solaris, also support multiple partitions. Each partition can be formatted with a specific file system or used as a swap partition. A swap partition provides extra space for the system to use when memory is low. In Linux, a common minimal setup uses three distinct partitions. The first is the root directory, mounted on "/", which holds system files. The second is the home directory, mounted on "/home", which holds user data. The third is the swap partition. Using this method protects data; if one file system becomes corrupted, data in other partitions may remain intact.

Historically, disk segmentation has been used for decades. In 1966, IBM used a method called "minidisk" in its CP-67 operating system. Data General later used the term "partition" for subregions in its Nova computers. These partitions each contained their own directory. In 1983, IBM released PC DOS version 2.0, which used the term to describe dividing block storage devices. Today, the term is used universally, though sometimes called slices, sections, or virtual drives. In the Solaris operating system, partitions are often called slices, similar to pieces of a cake.

Modern computers frequently use the GUID Partition Table, or GPT. This is part of the Unified Extensible Firmware Interface (UEFI) standard. GPT is used for the layout of partition tables on physical hard disks. Many modern operating systems support this standard, though Windows does not support it on BIOS-based computers. Before GPT became common, many PCs used the Master Boot Record (MBR) scheme. Under MBR, a disk can contain at most four primary partitions. Alternatively, it can hold three primary partitions and one extended partition. The MBR contains 16-byte entries that describe each partition's type and location.

Users can also create multi-boot systems using partitioning. A multi-boot system allows a user to boot into more than one operating system. These operating systems are stored in separate partitions or on separate storage devices. At startup, a menu appears to let the user choose which system to load. This is different from a virtual machine, which runs as a program inside an already running operating system. Finally, it is possible to recover lost partitions. When a partition is deleted, its entry is removed from the table, but the data remains on the disk. Specialized recovery utilities can sometimes locate these lost file systems and recreate the partition table.