An introduction to remote-boot
What is remote-boot ?
A remote-boot computer is a computer that does not relies on local
ressources (such as its hard disk) to start, but uses centralized
remote ressources (through the network) instead.
Remote-booting is generally a three phases process :
- Information gathering about the client's configuration. In this phase
the client computers establish a communication with a server,
using either the
BOOTP or the
DHCP protocol, in order to
get the basic information needed to proceed to the next stages.
This critical information includes the IP address, subnet mask,
default gateway and the name of the bootstrap program to load.
- Downloading the bootstrap program. The
is the core of the remote-booting process.
It is permanently stored on the server's hard disk, and
transfered to the client computer on demand using the
Its task is to prepare the client to run the operating system,
as configured by the system administrator.
- Executing of the bootstrap program, which will typically
leads to the download of the operating system,
partitioning and formatting the hard disk and
launching the operating system.
These three phases are directed by a chip installed on the network
card, called a bootrom.
It works in tight interaction with the computer BIOS
and provides basic IP/UDP connectivity,
as needed to accomplish its tasks.
Links and related documentation
- Intel WfM site
Home of the PXE specification. Go there if you want to get latest PXE
NILO is a project which purpose is to build a free PXE-compatible
bootrom based on Linux network drivers.
Netboot is a free bootrom package which can be used to boot Linux
on a single computer. Its scalability is however very limited.
An alternative to netboot, with similar limitations.