[CentOS] Replacing failed software RAID drive

Les Mikesell lesmikesell at gmail.com
Wed Oct 10 23:37:01 UTC 2007

Hugh E Cruickshank wrote:
> From: Les Mikesell
>> Hugh E Cruickshank wrote:
>>> From: Les Mikesell Sent: October 7, 2007 18:53
>>>> Then reinstall grub on the drive.
>>> Now I have some questions:
>>> 1. Since the /boot partition was mirrored and will be restored on the
>>>    new sda drive I do not really want to do a full grub install. From
>>>    what I have read that will overwrite existing /boot/grub/grub.conf
>>>    file. So I just want to write the MBR on the drive. How to I do
>>>    that (the docs I have found were rather unclear on that aspect)?
>>> 2. Can a install grub on the replaced boot drive with the system still
>>>    running?
>> Yes, after the /boot partition re-sync has completed, execute grub and:
>> root (hd0,0)
>> setup (hd0)
>> quit
>> If you aren't able to keep the system running while doing the swap, you
>> can also do this from the rescue mode boot, but you should have the
>> contents on the /boot partition first.
> Sorry to be obtuse here but I just want to make very sure of what I am
> doing before I do it. Will the "setup" command only write the MBR?

Yes, it will verify that the root partition (grub calls /boot root since 
that's all it knows about) looks right, then write the MBR.

   Les Mikesell
    lesmikesell at gmail.com

More information about the CentOS mailing list