Enter diskless booting. Diskless booting is an attractive solution because it allows for complete control of the system disk when performing the upgrade. The disk can be reformatted, repartitioned, mounted, unmounted, etc. at will. However, diskless booting is not without its problems. The booting protocol requires that the upgrade server be located on the same logical network as the client being upgraded.
Many simultaneous upgrades can place an undesirable load on the network.
The next section describes how we worked around the former problem. For the latter problem, we place limits on the number of simultaneous upgrades at the expense of time. The Upgrade Procedure Doing upgrades is a three-step process. First, you need to configure each upgrade server to support diskless clients. Then, you must do a prototype installation for each different type of environment you are supporting.