[Techtalk] I want to install Fedora Core 3 but can't boot from scsi cdrom

conor.daly at cod.utvinternet.com conor.daly at cod.utvinternet.com
Thu Feb 10 21:51:22 EST 2005

On Wed, Feb 09, 2005 at 03:17:50PM -0800 or so it is rumoured hereabouts, 
Darlene Wallach thought:
> I guess I don't understand why to do the loopmount - is
> that just to see what is there?
> Thank you very much for the instructions in the previous
> email. I copied the vmlinuz and initrd.img files to /boot
> and modified grub.conf. I was thinking there had to be an
> easy solution. I now feel very silly since I have modified
> grub.conf to boot from a different kernel.

The loopmount is so you can get at the vmlinuz and initrd.img that you're
going to use to boot from.  Where did you get the files you copied?  When
you say you modified grub.conf, do you mean to say you changed the
existing boot config rather than adding an extra one?  Ooops!  You'll be
able to boot your original system in any case by using the grub shell at
boot time.  My RH9 grub.conf has two sections, one to boot the system and
one to boot the FC3 installer (I plugged the spare disk into this machine
to start the install...).  Each section looks like this:

title Red Hat Linux (2.4.20-8)
        root (hd0,0)
        kernel /boot/vmlinuz-2.4.20-8 ro root=/dev/hda1 hdc=ide-scsi
        initrd /boot/initrd-2.4.20-8.img
title Fedora Core 3 install
       root (hd0,0)
       kernel /boot/vmlinuz-FC3-install text askmethod
       initrd /boot/initrd-FC3-install.img

The "Red Hat Linux" section boots my main kernel and your main kernel will
look similar but with different version numbers.  The "Fedora Core 3
install" section boots the installer's kernel instead.  You need to modify
your grub.conf so that you have both sections.  This actually won't matter
once the upgrade happens since it will overwrite your grub.conf but, in
the meantime...

Since you can't boot your RH7.3 kernel at present, you can go about things
two ways.  1.  Boot interactively using grub.  2.  Boot the installer,
mount your current partitions, edit grub.conf and reboot.

1.  Interactively using grub
o boot the machine, at the grub screen, press 'e' to edit
o select the 'kernel' line and press 'e' again to edit
o Set the kerenl line to the correct vmlinuz-... root=/dev/hd... and press
o select the 'initrd' line and press 'e' to edit
o set the initrd line to the correct initrd... and press <enter>
o press 'b' to boot
o once booted, edit /etc/grub.conf to include correct values.

2.  Using the FC installer
o boot the machine, at the grub screen, press 'e' to edit
o select the 'kernel' line and press 'e' again to edit
o remove the 'askmethod' keyword and instead type 'rescue' and press
o press 'b' to boot
o once booted, it should tell you where your original system is mounted
  it may even do a chroot <wherever your system is>
o edit /etc/grub.conf to include correct values.
o type 'exit' to reboot.

That should get you back to being able to boot your RH7.3 system.  Of
course, you could just go ahead and run the FC3 installer and do the
system upgrade...

Conor Daly <conor.daly at oceanfree.net>

Domestic Sysadmin :-)
 10:34:05  up 2 days, 21:54,  1 user,  load average: 0.04, 0.03, 0.00

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