C.2 Boot Floppies

Even if you don't want to boot Linux from a floppy diskette, you should create and keep on hand a Linux boot floppy. If something goes wrong with your system, preventing you from booting in the normal way, you may be able to boot your system by using the floppy. Then, you can diagnose and repair the problem and get back to business as usual.

C.2.1 Creating a Boot Floppy

The Red Hat install program gives you the option of creating a boot diskette when you install Linux. You should exercise this option each time you install Linux, so that you have a fresh boot floppy containing software consistent with that stored on your hard drive.

However, you can easily create a boot diskette after the installation is complete. To do so, insert a blank floppy diskette into your system's floppy drive. Log on as root and issue the following command:

# /sbin/mkbootdisk  version 

For version, supply the version number of your kernel. If you don't recall the version, execute the following command, which reports it:

# uname -a

The version number resembles the version number of an RPM package. For example, a typical kernel version number is 2.4.18-14.

The mkbootdisk command creates a boot floppy that uses the same kernel running when the command is issued. It also configures the boot floppy to load any necessary SCSI modules, so that your SCSI drives will be accessible after booting from the floppy.

C.2.2 Using a Boot Floppy

Insert the boot floppy into your system's floppy drive. If your system is turned off, power up your system. If your system is turned on, first shut down the active operating system in the proper manner, then restart the system. Linux should then boot from the floppy.

To use your boot floppy, your system's CMOS must be configured to allow booting from the floppy drive. If your system boots from its hard drive even when the boot floppy is present, you must change your system's CMOS configuration. The relevant option is generally named Boot Sequence, Boot Order, or something similar. The value you want is generally labeled A:, C:, or something similar. Consult your system's documentation for further information.