Re: How to get system back after grub fail

[Felix Miata]

On 2011/08/11 16:03 (GMT-0600) J.V. composed:

> I just want my system to boot again and to use grub to boot off of one
> of three drives in the system.  Is this possible?

Sure! Have you tried detaching (simply pull each power plug from the HD) the 
2 HDs that CentOS was not installed to and trying to boot that way?

If that doesn't work, try again after doing a _complete_ BIOS reset to 
defaults, which may require removing both power to power supply and the 
motherboard battery for several minutes. Once the reset has been done, make a 
note of the HD and HD controller configuration settings in the BIOS, and the 
boot device order.

You haven't provided materially better information today than when you asked 
Wednesday. To best assist us in helping you, we need more information.

1-output of 'fdisk -l' while booted to rescue mode of your CentOS DVD, 
annotated with what is installed where. Because most likely you'll be copying 
from screen rather than saving this as a file to attach, you need not provide 
all the numbers delineating sizes, but merely the logical partitioning/layout 
of all three disks.

2-booted to CentOS DVD, from the rescue prompt, enter command 'grub'. At the 
'grub>' prompt, type in 'find /boot/grub/stage1', and give us that output. 
(to exit grub shell, type "exit")

3-booted to CentOS DVD, from the rescue prompt, enter command 'grub'. At the 
'grub>' prompt, type in 'find /boot/grub/device.map'. If it provides output, 
make a note of that output, exit the grub shell, then mount each partition on 
which one is found, and give us the output of each such device.map file found.

4-what are each of the 3 HDs attached to? All PATA? All SATA? A mix of SATA & 
PATA? A mix of SATA & PATA & USB? Provide details.

5-If your system is a mix of SATA and PATA, describe the configuration of 
those disks and controllers in the PC's BIOS.

BTW, you should not need to execute 'grub-install /dev/sda' after a fresh 
installation. Grub should have been properly installed during installation, 
but may not have been because of the multi-HD environment it found. Grub and 
Linux commonly do not agree on HD order at boot and run time, which may be 
the root of your problem. An OS version as new as CentOS 6 should not have 
this problem, but nevertheless it would come as no surprise to me if it is.
--
"The wise are known for their understanding, and pleasant
words are persuasive." Proverbs 16:21 (New Living Translation)

 Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

Felix Miata  ***  http://fm.no-ip.com/