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Re: How to get system back after grub fail


From: Felix Miata
Subject: Re: How to get system back after grub fail
Date: Thu, 11 Aug 2011 19:11:09 -0400
User-agent: Mozilla/5.0 (OS/2; Warp 4.5; rv:6.0) Gecko/20110731 SeaMonkey/2.3

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/



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