Triple boot and GRUB puzzle
 

Greetings,

I have an interesting issue and I don't know if it can be easily resolved.

System brief: I have a Dell P4 with three hard drives.

Initially, both drive 1 and drive 2, 40 GB and 60 GB respectively total 100 GB, were dedicated to Win2k alone. I then decided to install Fedora Core 2 using GRUB. I repartitioned my 60 GB hard drive (drive 2) to make room for Linux. GRUB ran in the MBR and all was well.

I added a third hard drive, 160 GB principally for my Linux O/S. My thought was to install Fedora Core 3 on the new drive and reallocate the 60 GB to Win2k.

First question: can this be accomplished? That is to say, can I, having GRUB already installed and its configuration files in my Core 2 partitions, switch to my Core 3 partitions?

Second question: until I can achieve my goal in question 1, I would like to boot into the new Core 3 installation. After learning (actually hacking at) GRUB on the fly, I figured out how to recognize the new disk by editing the device configuration file. However, when I finally got GRUB to launch the new O/S, it started to boot the correct kernel but then started using my existing Core 2 partitions rather than the Core 3. What have I done wrong here?

Third question: if I cannot accomplish my reallocation goals, can I easily yank GRUB out of my MBR and start fresh without reinstalling Win2k, which would certainly raise my distaste for Microsoft O/S's to new level)?

Thanks in advance,

Thomas

IF, big if here, I understand you correctly, you just install the new OS and add it to your grub.conf file. It sounds doable. I have moved Gentoo and Mandrake aroung quite a bit with no problem. I did leave Mandrake behind the last time though. Gentoo only now.

Sounds doable.

Oh, BUMP.

:D :D :D :D :D

Should work...let's see that grub.conf file

hello friend!

the replies for your questions:-



First question: can this be accomplished? That is to say, can I, having GRUB already installed and its configuration files in my Core 2 partitions, switch to my Core 3 partitions?

Ans:- it is possible, you can boot into fedora core 2 or fc3 at the time of start up.


Second question: until I can achieve my goal in question 1, I would like to boot into the new Core 3 installation.

Ans :-You will have three o/s fc3 , fc2 and ur windows and you can select one o/s to boot at the system start up!


Third question: if I cannot accomplish my reallocation goals, can I easily yank GRUB out of my MBR and start fresh without reinstalling Win2k, which would certainly raise my distaste for Microsoft O/S's to new level)?

yes:- boot from winnt2000 o/s cd and Use recovey consol option.
in your c: partition (win) give <fixmbr>
this "fixmbr" will fix your master boot record and ur winnt is back.



now if you want to use three operating systems all you have to do is some changes in ur /boot/grub/grub.conf file


default=0
timeout=10
splashimage=(hd0,0)/grub/splash.xpm.gz

# section to load Fedora Core3
title FedoraCore3 (2.4.21-1.ent)
root (hd0,0)
kernel /vmlinuz-2.4.21-1 ro root=/dev/hda2
initrd /initrd-2.4.21-1.img



# section to load Fedora Core2
here remember to give the same location of your Fedora
Core2 configuration of root (hdx,x) and your kernel location
kernel/vmlinuz-x.x.x.x.x ro root=/dev/hdax whatever.
The basic point here is to just to the type the whole portion of your fedora core 2 config file between title and ur initrd line into your fedora core 3 /boot/grub/grub.conf file.
also remember now you have only one grub which will work for you (here in this case i am editing my /boot/grub/grub.conf of my Fedora core3 so my fedora core3 will handel the o/s selection part at the system startup).



title Fedora Core2 (x.x.x.x.x.)
root (hdx,x)
kernel /vmlinuz-x.x.xx-x ro root=/dev/hdxx
initrd /initrd-x.x.xxx-x.img

# section to load Windows
title Windows
rootnoverify (hd0,0)
chainloader +1





I am using four operating systems on my pc (winnt , winnt2000, Redhat Linux ws , and Fedora core3) and my grub shows me three options First is to boot Redhat linux, second is Fedora core 3 and third is windows and from windows I can select winnt2000 or winnt ) and have two hdd's of 40GB.
One more thing ...personally I save my data on my second hdd and operating systems on the first one so that my data is still safe on my second hdd.

At the time of installation I installed windows first > then redhat > and then fc3
KEY POINT HERE BEFORE THE TIME OF INSTALLING YOUR FEDORA CORE3 DON'T FORGET TO NOTE DOWN UR /boot/grub/grub.conf file (here in this case i will note down a portion of my redhat's grub configuration /boot/grub/grub.conf which gives me the loacation of Redhat's kernel .
i.e.

#section to load Redhat
title Redhat Linux(x.x.x.x.x.)
root (hdx,x)
kernel /vmlinuz-x.x.xx-x ro root=/dev/hdxx
initrd /initrd-x.x.xxx-x.img
now when i am going to install my Fedora core3 it has it's own grub (coz i selected to install a new bootloader for fedora core 3)
now after finishing my installation ...and reboot i can see only two options as i still have to edit my grub configuration file (/boot/grub/grub.conf of fedora core3) i.e. simply i have to give this grub(Fedora core3's) the information about the loaction of My Redhat's kernel location.
Therefore after booting into fedora core3 I edited my grub configuration file and just entered the information about my redhat's kernel location (which I noted down previously from my redhat's /boot/grub/grub.conf file)

#section toload Redhat
title Redhat Linux(x.x.x.x.x.)
root (hdx,x)
kernel /vmlinuz-x.x.xx-x ro root=/dev/hdxx
initrd /initrd-x.x.xxx-x.img



___________________________________________

the result would look like


default=0
timeout=10
splashimage=(hd0,0)/grub/splash.xpm.gz

# section to load Fedora Core3
title FedoraCore3 (2.4.21-1.ent)
root (hd0,0)
kernel /vmlinuz-2.4.21-1 ro root=/dev/hda2
initrd /initrd-2.4.21-1.img


#section to load Redhat
title Redhat Linux(x.x.x.x.x.)
root (hdx,x)
kernel /vmlinuz-x.x.xx-x ro root=/dev/hdxx
initrd /initrd-x.x.xxx-x.img

# section to load Windows
title Windows
rootnoverify (hd0,0)
chainloader +1

keypoint: You have to give the location of the kernel file to load when booting the operating system.In the grub configuartion file.


cheers:)

As a personal preference, if I have multiple OS's running around, I install one with grub to my primary master MBR (first hard disk MBR). From there I chainload to the other mbr's and boot sectors.

This way I can go ahead and let each operating system take care of it's own boot loader without interfering with one another. I don't know about the fedora core installer, but I would have it install grub to the MBR of the third disk, and then alter your original GRUB menu to include a chainloader command on disk three (as though you were loading windows).

I'm not sure I understand you. I kinda hope that I don't. You shouldn't be randomly hacking at the device.map file. I don't think you need to touch this file at all (except to change it back). xxx_anuj_xxx has the right idea. On some systems it is /boot/grub/grub.conf and on others it is /boot/grub/menu.lst (find the one that you have and edit it instead, you may need to add an entry to device.map for your third disk - I doubt it, but you shouldn't need to alter one of the entries already there).

If grub is not doing what's expected then when it boots you will need to check the options in the menu.

Pressing esc will get you out of the boot screen and pressing e will get you into edit mode of the selected image.

You can correct the settings there and then boot the new settings by escaping out of edit mode and pressing b

boot into the distro where you last installed grub to the mbr and change the menu.lst file there. Confirm that it is the one being used by comparing it's contents to what you see at boot.

You can also reinstall from any other system where you have grub available.


/dev/hda1 = (hd0,0)

hd0 = the drive and the second number is the partition

In the kernel line the option root=/dev/hd?? is the root filesystem.


Be sure where your filesystems are then edit the file as needed.


Grub can multi boot a very large number of OSes, I can't recall the nunber at this time.

http://www.wbglinks.net/pages/reads/linux/grub.html

David,

This was the key; thanks for you help. My root was wrong as well as the location where the kernel image was located.

Wrong configuration was something like (don't have it front of me as I neglected to find out what the system's initial hostname was and I'm working remotely now):

title FedoraCore3...
root (hd0,0)
kernel /boot/vmlinuz-2.x... ro root=LABEL=/ ...
initrd /boot/initrd-2.x....img

Corrected contiguration:

title FedoraCore3...
root (hd0,0)
kernel /vmlinuz-2.x... ro root=/dev/hdd3 ...
initrd /initrd-2.x....img

fdisk and mount helped me confirm the partion.

Thanks for you help!

Now that I succeeded in booting the new O/S, I will probably (still undecided) restore the Windows boot loader, wipe out my FC2 since I have backed just about everything up, and then I'll reallocate my disks for a bigger Windows and a dedicated 160 GB FC3. Then I'll use GRUB again and the multi-boot driver in the FC3 partition.

Regards,

Thomas

Yep,

That's usually the first thing I do is change the partition label to the device.

It could go either way I guess. If you use the device name and add or remove some partitions ahead of your / partition or if you swap some drives around then the label would save you some grief. However if you have two partitions with the same label you end up with the first one all the time. You would need to give the partitions unique labels. You would also need to do the same for all of your partitions and setup the labels in /etc/fstab for it to be useful.

The device name works good for me. I would recommend saving your partition and filesystem info in case you ever have a problem.