8.6. Emergency boot floppies
It is not always possible to boot a computer from the hard
For example, if you make a mistake in configuring LILO, you might
make your system unbootable. For these situations, you need an
alternative way of booting that will always work (as long as the
hardware works). For typical PCs, this means booting from the
Most Linux distributions allow one to create an
emergency boot floppy during installation.
It is a good idea to do this. However, some such boot disks
contain only the kernel, and assume you will be using the programs
on the distribution's installation disks to fix whatever problem
you have. Sometimes those programs aren't enough; for example,
you might have to restore some files from backups made with
software not on the installation disks.
Thus, it might be necessary to create a custom root floppy
as well. The Bootdisk HOWTO by Graham Chapman contains instructions
for doing this. You can find this HOWTO at
You must, of course, remember to keep your emergency boot and
root floppies up to date.
You can't use the floppy drive you use to mount the root
floppy for anything else. This can be inconvenient if you only
have one floppy drive. However, if you have enough memory, you
can configure your boot floppy to load the root disk to a ramdisk
(the boot floppy's kernel needs to be specially configured for
this). Once the root floppy has been loaded into the ramdisk,
the floppy drive is free to mount other disks.