[clug] boot time issue

[David Tulloh]

Benedict and Trisha Wyss wrote:
> Hi all,
> 
> this is my first posting of the questioning type so bear with me.
> 
> I have just built fresh a rh8 box on a compq pro workstation. Unfortunatly
> durring boot it will only see the MBR every now and then and always with the
> recovery disk otherwise producing the following error "No System disk or
> disk error replace and strike any key when ready". I am reasonably happy
> that sda's boot sector etc are ok and functioning as it works perfectly with
> the diskette. My question here is do I rebuild and hope this rectifies the
> issue or is there a repair tool known to you guys??

Ok:
boots with disk
doesn't boot with hard drive (I'm a little worried about the 'now and then')

I suspect the problem is that grub is not installed in the mbr.  During 
the installation process you are presented with a choice of installing 
the boot loader into the MBR or the boot partition, in which case you 
would need to use another boot loader in the MBR.  I suspect that you 
have chosen to put grub in the boot partition rather than the MBR, 
leaving the MBR empty... hence the no disk found error.  I'm hoping that 
someone else can provide a second opinion on this matter.

It is possible to fix this problem using the grub shell.
I hesitate to provide any specifics as the commands given vary on your 
hardware layout and it would be very easy to hurt something if I assumed 
anything about your layout.  Instead, some further reading:
http://www.gnu.org/software/grub/manual/
http://www.mcc.ac.uk/grub/grub_toc.html  (same as above, but works)
http://www.fr.linuxfromscratch.org/view/lfs-5.0/chapter08/grub.html


> 
> The other point is there are 2 entries in grub.conf (see below) and am
> wondering why or what is the difference when booted?
> ____________________________________
> title Red Hat Linux (2.4.18-14smp)
> 	root (hd0,0)
> 	kernel /vmlinuz-2.4.18-14smp ro root=LABEL=/ vga=0x314
> 	initrd /initrd-2.4.18-14smp.img
> title Red Hat Linux-up (2.4.18-14)
> 	root (hd0,0)
> 	kernel /vmlinuz-2.4.18-14 ro root=LABEL=/
> 	initrd /initrd-2.4.18-14.img
> _____________________________________

The smp kernel version is for multi-processor systems.  If you only have 
one processor the bottom option is faster, however both should work. 
You can delete whichever option you do not use.

Hope it all works out for you.
David