Can't Boot Grub Prompt

pmrent · 02-09-2005, 04:37 PM

I used a windows boot disk and image client 32 to create an image back up of my linux RHE3 ES. I was restoring the back up to another server and all I get is the grub prompt. I'm assuming I corrupted the mbr.

How do I fix this?

Install the Redhat enterprise linux 3 es install disk #1 and type in linux rescue

Then what?

thanks in advance for your help.

-pete

bulliver · 02-09-2005, 08:07 PM

If you have a grub prompt then you can boot your kernel manually. And I would say it is much more likely you have a malformed or missing grub.conf file rather than any corrupted mbr.

Assuming your kernel is in a /boot partition on /dev/hda1 you would do this:

Code:

grub> root (hd0,0)
  Filesystem type is ext2fs, partition type 0x83
grub> kernel (hd0,0)/mykernel root=/dev/hda2 vga=791
  [Linux-bzImage, setup=0xa00, size=0x10b949]
grub> boot
....starts booting....

Remember that grub prompt has tab completion, so if you don't remember your kernel name:

Code:

grub> kernel(hd0,0)/[Tab]
   Possible files are: mykernel myotherkernel etc.....

Once you are booted fix your grub conf.

pmrent · 02-15-2005, 04:58 AM

Thanks for your help. I ended up rebuilding from scratch. After some more research symantix has problems with restores to different disk configurations. The image was taken from a 12 gig EMC disk partition and moved to a 8 gig Shark disk partition. I don't completely understand why this is an issue but it was in the knowledge base.

I have copied your idea into my personal faq database for future reference. I think manually booting is a good idea and I would like to try it anyways.

When I screw that up I'll reply back again.

Thanks

-pete

aus9 · 02-24-2005, 12:11 AM

my 2 cents worth.

when you do restores......you overwrite an existing partition so there is no need to overwrite the mbr.

pretending you had however, made larger patitions on machine 2 and were using images from machine 1 to restore machine 2
in the very worse scenario you may have to just redo grub in mbr to reset the correct block address for its booting files.

but if you always have /boot as the first partition and size is same for machine 1 to 2 imo grub in mbr is safe as is

btw I use www.partimge.org but off a knoppix cd