Network booting

From Wikipedia, the free encyclopedia

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2014) (Learn how and when to remove this template message)

Network booting, shortened netboot, is the process of booting a computer from a network rather than a local drive. This method of booting can be used by routers, diskless workstations and centrally managed computers (thin clients) such as public computers at libraries 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 incluster computing, in which nodes 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[edit]

Contemporary desktop personal computers generally provide an option to boot from the network in their BIOS via the Preboot Execution Environment (PXE). Post-1998 PowerPC(G3 - G5) Mac systems can also boot from their firmware to a network disk via NetBoot.^[1] Old personal computers without network boot firmware support can utilize a floppy diskor flash drive containing software to boot from the network.

Process[edit]

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. The server from which to load the initial software is usually found by broadcasting a Bootstrap Protocol or Dynamic Host Configuration Protocol request.^[2] 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 then load the full image by invoking the corresponding second-stage bootloader.

Installations[edit]

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 and Windows exist as NetInstall and Windows Deployment Services, respectively.

Network booting- 

short description from networkboot.org

What is network booting?

Network booting, or booting from LAN as it is also called, is a process which allows a computer to start up and load an operating system or other program directly from the network without any locally attached storage device, like a floppy, CDROM, USB stick or hard drive.

On Intel architecture computers this is made possible with the PXE standard. PXE extends the features of the BIOS so that it can run software directly from the network. PXE support is now so common that you can expect it to be present in any reasonably modern computer that comes with an Ethernet jack (commonly known as RJ45).

This fact alone makes it possible to boot an Intel-based computer from the network without having to burn an EEPROM on your network card, like you had to do in the past.