Network booting, shortened netboot, is the process of booting a computer from a

network Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

rather than a local drive. This method of booting can be used by routers, diskless workstations and centrally managed computers (

thin client In computer networking, a thin client is a simple (low-performance) computer that has been optimized for establishing a remote connection with a server-based computing environment. They are sometimes known as ''network computers'', or in th ...

s) such as public computers at

libraries A library is a collection of Document, materials, books or media that are accessible for use and not just for display purposes. A library provides physical (hard copies) or electronic media, digital access (soft copies) materials, and may be a ...

and schools. Network booting can be used to centralize management of disk storage, which supporters claim can result in reduced capital and maintenance costs. It can also be used in

cluster computing A computer cluster is a set of computers that work together so that they can be viewed as a single system. Unlike grid computers, computer clusters have each node set to perform the same task, controlled and scheduled by software. The compo ...

, in which

node In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics * Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines ...

s may not have local disks. In the late 1980s/early 1990s, network boot was used to save the expense of a disk drive, because a decently sized harddisk would still cost thousands of dollars, often equaling the price of the CPU.

Hardware support

Contemporary

desktop A desktop traditionally refers to: * The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor) Desktop may refer to various compu ...

personal computers A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...

generally provide an option to boot from the network in their BIOS/

UEFI UEFI (Unified Extensible Firmware Interface) is a set of specifications written by the UEFI Forum. They define the architecture of the platform firmware used for booting and its interface for interaction with the operating system. Examples of ...

via the

Preboot Execution Environment In computing, the Preboot eXecution Environment, PXE (most often pronounced as ''pixie'', often called PXE Boot/''pixie boot''.) specification describes a standardized client–server environment that boots a software assembly, retrieved from ...

(PXE). Post-1998 PowerPC ( G3 G5) Mac systems can also boot from their New World ROM firmware to a network disk via NetBoot. Old personal computers without network boot firmware support can utilize a floppy disk or

flash drive A flash drive is a portable computer drive that uses flash memory. Flash drives are the larger memory modules consisting of a number of flash chips. A flash chip is used to read the contents of a single cell, but it can write entire block of cell ...

containing software to boot from the network.

Process

The initial software to be run is loaded from a server on the network; for IP networks this is usually done using the

Trivial File Transfer Protocol Trivial File Transfer Protocol (TFTP) is a simple lockstep File Transfer Protocol which allows a client to get a file from or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a local area networ ...

(TFTP). The server from which to load the initial software is usually found by broadcasting a Bootstrap Protocol or Dynamic Host Configuration Protocol (DHCP) request. Typically, this initial software is not a full image of the operating system to be loaded, but a small network boot manager program such as PXELINUX which can deploy a boot option menu and then load the full image by invoking the corresponding second-stage

bootloader A bootloader, also spelled as boot loader or called boot manager and bootstrap loader, is a computer program that is responsible for booting a computer. When a computer is turned off, its softwareincluding operating systems, application code, an ...

Installations

Netbooting is also used for unattended operating system installations. In this case, a network-booted ''helper operating system'' is used as a platform to execute the script-driven, unattended installation of the intended operating system on the target machine. Implementations of this for

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and la ...

and

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ser ...

exist as

NetInstall NetBoot was a technology from Apple which enabled Macs with capable firmware (i.e. New World ROM) to boot from a network, rather than a local hard disk or optical disc drive. NetBoot is a derived work from the Bootstrap Protocol (BOOTP), and is ...

and

Windows Deployment Services Windows Deployment Services is a server technology from Microsoft for network-based installation of Windows operating systems. It is the successor to Remote Installation Services. WDS is intended to be used for remotely deploying Windows Vista, W ...

, respectively.

Legacy

Before IP became the primary

Layer 3 In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers. Functions The network layer provides the means of transfe ...

protocol, Novell's NetWare Core Protocol (NCP) and IBM's

Remote Initial Program Load Remote Initial Program Load (RIPL or RPL) is a protocol for starting a computer and loading its operating system from a server via a network. Such a server runs a network operating system such as LAN Manager, LAN Server, Windows NT Server, Nov ...

(RIPL) were widely used for network booting. Their

client Client(s) or The Client may refer to: * Client (business) * Client (computing), hardware or software that accesses a remote service on another computer * Customer or client, a recipient of goods or services in return for monetary or other valuabl ...

implementations also fit into smaller

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

than PXE. Technically network booting can be implemented over any of

file transfer File transfer is the transmission of a computer file through a communication channel from one computer system to another. Typically, file transfer is mediated by a communications protocol. In the history of computing, numerous file transfer protocol ...

or resource sharing protocols, for example, NFS is preferred by BSD variants.

References

External links

PXE specification
The Preboot Execution Environment specification v2.1 published by Intel & SystemSoft
Remote Boot Protocol Draft
draft of the PXE Client/Server Protocol included in the PXE specification
NetBoot
NetBoot 2.0: Boot Server Discovery Protocol (BSDP) {{Firmware and booting