[CentOS] How to move my MBR

Mon May 26 07:46:25 UTC 2008
Theo Band <theo.band at greenpeak.com>

Scott Moseman wrote:
> I copied over the MBR from hdc to sda.  I found a 4.4 LiveCD, but
> apparently its damaged so it wouldn't boot.  I attempted to put
> everything back and when I rebooted it went into a GRUB screen instead
> of a normal boot.  I had no idea how to get it to boot from there, so
> instead of taking the time to figure it out, I decided it was time to
> make the plunge to CentOS 5.  So I'm now on CentOS 5 and my old /home
> hard drive is completely history.  :)
>   
And you happy with this?
>> I also do not see an CentOS 4.x x86_64 Live CD; only i386.
>> Is it not really going to matter, 64b vs 32b, when using that?
>>     
Doesn't matter for grub. Grub can load any operating system. You can 
even install grub while running Windows XP (tried it once).
>>> Do I need to move the MBR, remove the old drive, and reboot from
>>> a LiveCD in order to have a reconfigure of grub correctly see which
>>> drive it should find to boot from?  Or can I do this before taking the
>>> system down for the drive removal?
>>>       
In principle this does not matter. Only the entries in grub.conf which 
make up the menu need to be changed. The menu entries will contain 
entries like "root (hd1,0)" which you need to change to "root (hd0,0)" 
if you have only one disk in your system instead of two.
Once grub starts correctly, you can edit the menu entries as well. Just 
press the 'e' key and scroll to the line that is incorrect and change it 
until the system boots correctly. Permanent settings can be saved after 
your boot in /boot/grub/grub.conf.

Anyway you are now happy with Centos5?

Cheers,
Theo