re-installing GRUB
 

Hi everyone,

I would like to find out the correct, safe way to re-install the GRUB boot loader. I already have a working redhat 9 system, and I've been using a commercial program (system commander) to handle booting into either my windoze XP or Redhat partition. However, I periodically have problems with system commander, and I would like to go back to GRUB.

What's the right way to re-install GRUB. I know there is a "grub-install" command, but I read the GNU webpage documentation which made it sound like this approach had a high likelihood of leaving my system in an unbootable state. I know too that I could re-install RH9 from scratch, and ask for the GRUB loader, but the installation program doesn't give me the option of just installing the loader, and instead I have to do a full upgrade of the system, which takes many hours and might override some of my current settings.

Being somewhat of a newbie I don't want to screw this up. Also I never had to know the devices for my different partitions with my current boot loader, but I suspect I'll need this info to re-install GRUB (unless there's a way to auto-detect the operating systems). Is there a simple way to find out where XP and RH9 sit (i.e. hda1 etc...) from within linux?

I would greatly appreciate any suggestions you might have, and I thank you in advance.

To find out the device names:

fdisk -l

(-l = small L)

Thank you Skyline. I never used that option before. Looks good.

Newbix: No doubt, red hat support knows what they're doing. However, I've used grub-install several times without harm and have seen it suggested half a dozen times. If it's that or a reinstall, try it.

Thanks Skyline and misophist,

I'll gather up my courage and try your suggestions before my next reboot. I'll post the outcome either way for reference.

Cheers.

But make boot floppy first...

don't worry just try
/grub-install /dev/hda

If this makes any problem .. ask here .. I ll tell u how to install grub without using "grub-intall" utility.

Hi Everyone,

and thanks RickyJaff for the suggestion about the boot diskette. Well, I took the plunge and there is only a small snag which I hope someone can help me with:

I did "grub-install /dev/hda", and rebooted and I do get the GRUB selection window with the choices:

2.4.20-6bigmem
2.4.20-6smp
DOS

Which is almost what I need. The problem is that I no longer get the option to log in under the plain "2.4.20-6" kernel, which is the one I've been using. So for example, if I log in under bigmem or smp, I can't bring up the X-window interface because I installed my NVIDIA drivers under 2.4.20-6. I could re-install the drivers, and I suppose anything else that needs to be updated, but I'd rather know why I don't see 2.4.20-6 as an option anymore, and if there's a way to fix that.

Please Help! :eek: Many thanks in advance!

I think you need an entry in /boot/grub/menu.lst. It should be OK to use the others for a model.

Success!
 

Thanks misophist,

That did the trick! I modified /boot/grub/menu.lst as you suggested and I'm back in business.

And thanks again to Skyline and RickyJaff!

:cool: !

Well! we are here !!

Anytime!!