Red Hat Knowledgebase

If you have configured your system in such a way that you cannot break the boot process and your system is failing, it is easiest to boot to a recovery mode using a rescue disk. Using the rawwrite or dd utilities found on the first CD-ROM, go to another system and write the bootdisk.img file to the disk. The following commands are examples:

dd if=./bootdisk.img of=/dev/fd0 bs=512 count=2880
rawwrite bootdisk.img

Once you have the boot disk created, insert it in the failing machine and boot from the floppy drive. (You may have to modify your BIOS if your system is not configured to check the floppy drive during the boot sequence.) When the linux prompt appears, enter the words linux rescue.

The system will boot into rescue mode and mount your root filesystem under /mnt/sysimage. From here you can reconfigure your bootloader (LILO or GRUB) to have a longer timeout and reinstall it on the master boot record. When you reboot the system and remove the floppy drive you should be able to interact with your bootloader.