13.5 Creating Boot CDs

If problems occur booting your system using a boot manager or if the boot manager cannot be installed on the MBR of your hard disk or a floppy disk, it is also possible to create a bootable CD with all the necessary start-up files for Linux. This requires a CD writer installed in your system.

Creating a bootable CD-ROM with GRUB merely requires a special form of stage2 called stage2_eltorito and, optionally, a customized menu.lst. The classic files stage1 and stage2 are not required.

Creating Boot CDs

Change into a directory in which to create the ISO image, for example: cd /tmp
Create a subdirectory for GRUB:
```
mkdir -p iso/boot/grub
```

Copy the kernel, the files stage2_eltorito, initrd, menu.lst, and message to iso/boot/:

cp /boot/vmlinuz iso/boot/
cp /boot/initrd iso/boot/
cp /boot/message iso/boot/
cp /usr/lib/grub/stage2_eltorito iso/boot/grub
cp /boot/grub/menu.lst iso/boot/grub

Adjust the path entries in iso/boot/grub/menu.lst to make them point to a CD-ROM device. Do this by replacing the device name of the hard disks, listed in the format (sd*), in the pathnames with the device name of the CD-ROM drive, which is (cd):
```
timeout 8
default 0
gfxmenu (cd)/boot/message

title Linux
   root (cd)
   kernel /boot/vmlinuz root=/dev/sda5 vga=794 resume=/dev/sda1 \
   splash=verbose showopts
   initrd /boot/initrd
```
Use splash=silent instead of splash=verbose to prevent the boot messages from appearing during the boot procedure.

Create the ISO image with the following command:

mkisofs -R -b boot/grub/stage2_eltorito -no-emul-boot \
-boot-load-size 4 -boot-info-table -o grub.iso /tmp/iso

Write the resulting file grub.iso to a CD using your preferred utility. Do not burn the ISO image as data file, but use the option for burning a CD image in your burning utility.