Multibooting: I need some GRUB tips, thanks...
 

1. I am multibooting Linuxes over several hard drives all partitioned up into Primary and Extended partitions with Logical partitions within.

Well, I just filled my second disk, (hd1) and I don't know how to figure out(or where to find a table) to help me figure out what my other disks and partitions are reckoned as by GRUB (my bootloader). So far, I have filled hda (hdo) and hde (hd1) but I can't imagine what GRUB would name my hdg, hdk, hdi, etc... (I have 6 disks)


2. Secondly, I do just fine when the GRUB entry of a new disk is like
title SUSE
root (hd1,2)
chainloader +1

but I get completely lost and simply cannot boot distros that need all kind of vmlinuz, initrd, etc... info to boot. How do you figure out what a distro needs? (i.e. to fill in the GRUB menu.lst)

Can you help?

B.

First of all if you have the installer (of the distro(s) your installing) install grub to the root partition you can then chainload from your active grub rather than doing more work that is.
To find out how your disks are seen in grub you can open grub. Just type 'grub' in a shell and then 'find /boot/grub/stage1' of course that depends on having done what I suggested first i.e installing to the root partition.
Also take a look at the output of 'fdisk -l' as long as you understand that grub starts counting from zero you should be able to figure it out.
BTW your 1st ide drive is not "hdo" as you typed it. grub would see it as hd0 and the drive with partitions is hd0,X where X is the specific partition #.
Actually I think that fdisk command will give you the system order of your disks. So the order fdisk lists them in should be top to bottom the 0-5 numbers of your drives.

1. Look at the /boot/grub/menu.lst file

2. Install the bootloader to the / partition instead of the MBR for each linux you install after the first one. Then you should never need to use the initrd or vmlinuz, just the chainloader +1 entry. But basically, each linux you want to boot needs an initrd and a vmlinuz from their / partition to boot. So that's what you put in there. If you recompile your kernel, you may not need the initrd anymore...

Check out these two links for more help.
http://www.justlinux.com/forum/showt...hreadid=143973
http://www.justlinux.com/forum/showthread.php?t=144294

If you want to know how Grub calls your disks just invoke a Grub prompt and use the "geometry" command. Say you want to know the 1st and 2nd disk just type
By looking at the partitions you can be sure your disk order from the mouth of the horse (Grub in this case).

Grub names the disks exactly in the order handed down by the Bios.

If you have only two disk hda and hde ( In Linux convention ) It will still be named (hd0) and (hd1) in Grub. You must have hdb and hdc hooked to the CD and DVD rom.

Also inside every Grub installation there should be a file /boot/grub/device.map that maps the disks order. You can take a look there too.

pljvaldez has spelled the multi booting the easy way, by chainloading. That is an universal method (exactly the way Linux boots every Windows) for booting any PC system.

The last link of my signature has a range of booting tips I have collected and summarised.