System partition and boot partition

System partition and boot partition are computing terms for disk partitions of a hard disk drive that must exist and be properly configured for a system to operate correctly. There are two different definitions for these terms: Microsoft definition (used by Windows) and the common definition used by every other operating system.

Common definition

In context of every operating system, save those developed by Microsoft Corporation, system partition and boot partition are defined as follows:

• The boot partition is a primary partition that contains the boot loader, a piece of software responsible for booting the OS. For example, in the standard Linux directory layout (Filesystem Hierarchy Standard), boot files (such as the kernel, initrd, and boot loader GRUB) are mounted at /boot/.^[1] Despite Microsoft's radically different definition (see below), System Information, a utility app included in Windows NT family of operating systems refers to it as "boot device".^[2][3]
• The system partition is the disk partition that contains the operating system folder, known as system root. By default, in Linux, operating system files are mounted at / (the root directory).

In Linux, a single partition can be both a boot and a system partition if both /boot/ and root directory are in the same partition.

Microsoft definition

Since Windows NT 3.1^[4] (the first version of Windows NT), Microsoft has defined the terms as follows:

• The system partition is a primary partition that contains the boot loader, a piece of software responsible for booting the OS.^[5] This partition holds the boot sector and is marked active.^[6]:970
• The boot partition is the disk partition that contains the operating system folder, known as system root or %systemroot% in Windows NT.^[7]

A single partition may be both a system and a boot partition. In case they are separate, however, the boot partition does not contain the boot software and the system partition does not have the system root.^[6]:971

Before Windows 7, the system and boot partitions were, by default, the same and were given the identifier "C:". After Windows 7, however, Windows Setup creates, by default, a separate system partition that is not given an identifier and therefore is hidden. The boot partition is still given "C:" as its identifier. This configuration is suitable for running BitLocker, which requires a separate, unencrypted system partition for booting.

See also

• Windows NT startup process
• Windows Vista startup process
• Windows To Go

References

1. Petersen, Richard (2009). "Chapter 21: Basic System Administration". Ubuntu The Complete Reference. New York: McGraw-Hill. p. 473. ISBN 0-07-164368-0.
2. Andrews, Jean; Chellis, James. A+ Guide to Software (6th ed.). Cengage Learning. p. 21. ISBN 9781285414980.
3. Donald, Lisa (2008). MCSA / MCSE: Windows Server 2003 Environment Management and Maintenance Study Guide: Exam 70-290 (2nd ed.). John Wiley & Sons. pp. 116–117. ISBN 9780470327616.
4. "Definition of System and Boot Partition". Support. Microsoft. Retrieved 18 February 2016.
5. Tulloch, Mitch; Tulloch, Ingrid (2002). Microsoft Encyclopedia of Networking (2nd ed.). Redmond, WA: Microsoft Press. p. 1087. ISBN 0-7356-1378-8.
6. Russinovich, Mark E; Ionescu, Alex; Solomon, David A (2008). Windows Internals (5th ed.). Redmond, WA: Microsoft Press. ISBN 0-7356-2530-1.
7. Tulloch, Mitch; Tulloch, Ingrid (2002). Microsoft Encyclopedia of Networking (2nd ed.). Redmond, WA: Microsoft Press. p. 174. ISBN 0-7356-1378-8.

External links

• Definition of System Partition and Boot Partition (XP and Vista)