Grub noch mal neu installieren:
grub - shell starten : grub
dann "find /boot/grub/stage1"
Ausgabe beispielsweise (hd0,5)
root/boot Partition angeben: root (hd0,5)
grub in den MBR oder die Bootpartition installieren:
setup (hd0) --> MBR der ersten Festplatte
3.1 Creating a GRUB boot floppy
To create a GRUB boot floppy, you need to take the files stage1 and stage2 from the image directory, and write them to the first and the second block of the floppy disk, respectively.
Caution: This procedure will destroy any data currently stored on the floppy.
On a UNIX-like operating system, that is done with the following commands:
# cd /usr/lib/grub/i386-pc
# dd if=stage1 of=/dev/fd0 bs=512 count=1
1+0 records in
1+0 records out
# dd if=stage2 of=/dev/fd0 bs=512 seek=1
153+1 records in
153+1 records out
The device file name may be different. Consult the manual for your OS.
3.4 Making a GRUB bootable CD-ROM
GRUB supports the no emulation mode in the El Torito specification5. This means that you can use the whole CD-ROM from GRUB and you don't have to make a floppy or hard disk image file, which can cause compatibility problems.
For booting from a CD-ROM, GRUB uses a special Stage 2 called stage2_eltorito. The only GRUB files you need to have in your bootable CD-ROM are this stage2_eltorito and optionally a config file menu.lst. You don't need to use stage1 or stage2, because El Torito is quite different from the standard boot process.
Here is an example of procedures to make a bootable CD-ROM image. First, make a top directory for the bootable image, say, `iso':
$ mkdir iso
Make a directory for GRUB:
$ mkdir -p iso/boot/grub
Copy the file stage2_eltorito:
$ cp /usr/lib/grub/i386-pc/stage2_eltorito iso/boot/grub
If desired, make the config file menu.lst under iso/boot/grub (see Configuration), and copy any files and directories for the disc to the directory iso/.
Finally, make a ISO9660 image file like this:
$ mkisofs -R -b boot/grub/stage2_eltorito -no-emul-boot \
-boot-load-size 4 -boot-info-table -o grub.iso iso
This produces a file named grub.iso, which then can be burned into a CD (or a DVD). mkisofs has already set up the disc to boot from the boot/grub/stage2_eltorito file, so there is no need to setup GRUB on the disc. (Note that the -boot-load-size 4 bit is required for compatibility with the BIOS on many older machines.)
You can use the device `(cd)' to access a CD-ROM in your config file. This is not required; GRUB automatically sets the root device to `(cd)' when booted from a CD-ROM. It is only necessary to refer to `(cd)' if you want to access other drives as well.
Du kannst auch das Handbuch von grub durchlesen: