|
1. Introduction
2. Installation
3. Rescue
4. Tips and tricks
5. Configuration
6. Useful command
1.1. TAB autocompletion
Typing:
root (
and pressing TAB will display all possible partitions.
1.2. Accessing file
To specify the file /vmlinuz on the first partition on first hd:
(hd0,0)/vmlinuz
Installing GRUB on the system is not enough.
2.1. Installing GRUB on /boot
This step is mandatory.
Type:
grub-install
This will copy the boot images from /lib/grub/i386-pc to /boot/grub.
On Debian system this is automatically done installing the grub package.
2.2. Installing on MBR
To install GRUB on Master Boot Record, type:
root (hd0,0)
setup (hd0)
2.3. Installing in boot sector of a partition
To install GRUB in the boot sector of a partition without touching MBR, type:
root (hd0,0)
setup (hd0,0)
3.1. Making a GRUB bootable CD
mkdir -p iso/boot/grub
cp /lib/grub/i386-pc/stage2_eltorito iso/boot/grub
eventually make a menu
vi iso/boot/grub/menu.lst
Make ISO image:
mkisofs -R -b boot/grub/stage2_eltorito -no-emul-boot \
-boot-load-size 4 -boot-info-table -o grub.iso iso
Burn image grub.iso
3.2. Booting from GRUB shell
Given the following configuration:
/dev/hda1 is /boot
/dev/hda2 is /
Set root device:
root (hd0,0)
Load kernel:
kernel /vmlinuz-2.6.11-myhost root=/dev/hda2 vga=ext
initrd /initrd-2.6.11-myhost
Load modules:
module
or
modulenounzip
If the "kernel" command is called, modules has to be manually reloaded!
Start boot process:
boot
4.1. Colors
The colors can be changed with the following commands:
- foreground = RRGGBB
- background = RRGGBB
where RR, GG and BB are hex values for red, green and blue.
4.2. Splashimage
The configuration is very easy. Just place the splashimage somewhere, for example in /boot/grub/splash and add the following line to /etc/grub/menu.lst
splashimage=(hd0,0)/boot/grub/splash/debian-gnu.xpm.gz
Logically, replace(hd0,0) for your needs.
You can create your own splashimages. Just do the following things and follow the previous explained description:
- open an image
- resize it to 640x480 (with Gimp: Image -> Scale image)
- reduce color scale to 14 (with Gimp: Image -> Mode -> Indexed)
- save as .xpm
- compress the image with gzip image.xpm
Alternatively, you can download some already existing splash images from here: http://ruslug.rutgers.edu/~mcgrof/grub-images/images.
For a detailed howto, take a look here: http://ruslug.rutgers.edu/~mcgrof/grub-images.
4.3. Updating harddisk configuration
The harddisk configuration is saved in
/boot/grub/device.map
Review this file before using grub.
4.4. Trying new kernel
Take a look at http://www.gnu.org/software/grub/manual/grub.html#Making-your-system-robust.
4.5. Downloading OS images from network
Take a look at http://www.gnu.org/software/grub/manual/grub.html#Network
5.1. default
Set the default item to boot.
For example:
default 0
will boot the first item present in /boot/grub/menu.lst.
5.2. fallback
If the default boot item cannot be booted, try this one.
For example:
default 0
fallback 1
tries first item 0. If it fails, then tries item 1.
6.1. root
Specifies the partition where the boot images are placed.
If /boot is a own partition, you have to specify this partition and not the / partition!!!
6.2. kernel
Load the kernel.
For example:
kernel /vmlinuz-2.6.8-myhost
6.3. module
Load module file.
6.4. modulenounzip
Load module file without automatic decompression.
6.5. boot
Boot the loaded OS.
6.6. makeactive
Not really clear:
Set the active partition on the root disk to GRUB's root device. This command is limited to primary PC partitions on a hard disk.
6.7. savedefault
Not really clear.
6.8. mbchk
The program mbchk checks for the format of a Multiboot kernel. We recommend using this program before booting your own kernel by GRUB.
|
