When things go wrong, there are several ways to work on fixing them. However, they require that you understand the system well. This manual can't teach you what to do, but we will present the ways that you can use our products to get into rescue modes where you can use your own knowledge to rescue the system.
If your system boots, but does not allow you to log in when it has completed booting, you can use the single or emergency boot option. At the LILO boot: prompt, type linux single in order to boot in single-user mode. In single-user mode, your local filesystems will be mounted, but your network will not be activated. In emergency mode, almost nothing will be set up. Only the root filesystem will be mounted, and it will be mounted read-only.
The boot diskette created during installation of Red Hat Linux 5.1 may be used as part of a rescue diskette set. For more information, please read the file rescue.txt in the /doc on your Red Hat Linux 5.1 CD-ROM.
Have you ever rebuilt a kernel and, eager to try out your new handiwork, rebooted before running LILO? And you didn't have an entry for an older kernel in lilo.conf? Read on...
Here's a handy trick. In many cases, it's possible to boot your Red Hat Linux/Intel from the Red Hat Linux boot diskette with your root filesystem mounted and ready to go. Here's how:
Enter the following command at the boot diskette's boot: prompt:
linux single root=/dev/hdXX initrd=
(Replace the XX in /dev/hdXX with the appropriate letter and number for your root partition.)
What does this do? First, it starts the boot in single-user mode, with the root partition set to your root partition. The empty initrd specification bypasses the installation-related image on the boot diskette, which will cause you to enter single-user mode immediately.
Is there a downside to this trick? Unfortunately, yes. Because the kernel on the Red Hat Linux boot diskette only has support for IDE built-in, those of you with SCSI-based systems won't be able to use this trick. In that case, you'll have to use the boot/rescue diskette combination mentioned above.