The key to a remote upgrade is to be able to boot from floppy
disk to perform the upgrade, and then to reboot from the hard disk.
The possibilities are:
Most BIOSs allow the boot disk order to be
controlled through the BIOS' configuration. If
the BIOS supports a serial console then the
machine can be upgraded whilst leaving the floppy disk in the
drive. No one need attend the site to upgrade the operating
system
Someone can insert a floppy disk before the upgrade and
remove it afterwards. Most co-location sites will provide this
level of ‘board-swap’ technical support.
Two records of the CMOS memory which stores the
BIOS configuration can be made: one for booting
from floppy and another for booting from hard disk.
Unfortunately the nvram device driver does not yet work on a wide
enough variety of machines for this HOWTO to pursue this option
further.