"PXE (Preboot eXecution Environment) is Intel's loosely
defined standard for booting PCs over the network. A PXE-capable
BIOS or boot ROM can download bootstrapping code and load an
operating system over the network. Booting Linux with PXE is a
straightforward way of starting a diskless workstation or appliance
in a closed network.
Network booting is not the appropriate choice for all. However,
in an environment where the appliance will always be operating on a
high speed (>=10Mbit) LAN, it is an option worthy of examining.
There are two major advantages in opting for network booting over
local booting. First, storage is expensive, and solid-state storage
solutions (such as M-Systems DiskOnChip) are particularly so, where
the cost of 64M of storage may cost as much as a 20G hard
The other advantage comes in the form of administration. In the
case of a local storage device, upgrades must be done on every
single appliance. Network-based upgrades to local storage are
difficult to write, and administering the upgrade process can be a
long and tedious process. The alternative for local-storage clients
is to visit every client and make changes there. Obviously, this is
a time consuming task, and in many cases is not even a possibility.
Thus, a simple security update or configuration change may result
in hours or days of work to update all of the appliances."