Fedora Linux

The line in bold at the bottom of the listing is the encrypted (scrambled) version of the password.

Next, edit the /boot/grub/grub.conf file and add this line at the top, substituting the password you just generated:

password --md5 $1$f1z061$j/UEYyBn0e0996w0gjq4k/

When you boot the system, you will still be able to select a boot menu entry, but to perform any advanced operations (such as appending runlevel information to a boot entry), you will need to enter the password.

10.5.2. How Does It Work?

GRUB actually consists of four pieces of software, plus some utilities:

stage 1

The boot record. This tiny piece of code is less than 512 bytes long.

stage 1.5

Additional drivers for filesystems, such as ext2, to enable GRUB to find the stage 2 files.

stage 2

The standalone GRUB command shell and menu program.

/sbin/grub

A version of the GRUB command shell that can be executed inside a running Fedora system.

During boot, the system BIOS loads stage 1 as the boot record and executes it, which then loads stage 1.5 (if necessary) and finds stage 2 . stage 2 then seeks out the GRUB configuration file menu.lst (a symbolic link to grub.conf , which the Fedora developers apparently consider to be a better name).

The GRUB command shell supports over three dozen commands; most of these are never used except by experts and developers. Instead, most users interact with the GRUB menu.

The grub.conf file permits a set of boot options to be presented to the user as a menu entry, removing most of the complexity from the user's view.

A typical Linux entry in grub.conf sets the root filesystem, which is mounted by GRUB to enable access to the kernel and other boot drives. The entry also specifies the name of the kernel and initrd ramdisk to be loaded into memory, and also indicates any configuration options that are to be passed to the kernel.

10.5.3. What About...

10.5.3.1. ...an archive of GRUB splash images?

The author of the splash-image code maintains a small gallery of tested splash images at http://ruslug.rutgers.edu/~mcgrof/grub-images/images/ and an archive at http://ruslug.rutgers.edu/~mcgrof/grub-images/images/working-splashimages/ .

10.5.3.2. ...dual-booting between different Linux distributions?

This works well. Simply add the entries for the other Linux distributions to the active /boot/grub/grub.conf (or /boot/grub/menu.lst ) file. This can be done by specifying that the second Linux distribution install GRUB at the start of that distribution's root filesystem partition instead of placing it in the master boot record for the drive. Then copy the /boot/grub/grub.conf entries from the second Linux distribution to the first one.

10.5.4. Where Can I Learn More?

? The Grub manual: http://www.gnu.org/software/grub/manual/ (also installed as an info document in Fedora Core)

? The Grub web site: http://www.gnu.org/software/grub/

? The sample configuration file /usr/share/doc/grub-0.95/menu.lst

? The manpage for convert

10.6. Using Rescue Mode on an Installation Disc

The Fedora Core installation DVDor disc 1 of the CD setcan be used to boot into a rescue mode , which lets you access a Fedora system installed on a hard disk without booting from that hard disk. This can be used to recover from many types of system failure or badly misconfigured startup scripts.

10.6.1. How Do I Do That?

Inset your Fedora installation disc (DVD or CD 1) into the system and boot from it. At the boot prompt, enter:

boot: linux rescue

You will be presented with the standard language and keyboard menus (see Figures 1-5 and 1-6 in Chapter 1), and then the question shown in Figure 10-26 will be displayed.

Figure 10-26. Network interface question

If you want to be able to transfer files to and from the system (for example, to back up critical data), answer Yes; otherwise, answer No. If you answer Yes, the standard network configuration dialog will appear,