Hosed my MBR?

[Doug Poland]

On Tue, Apr 11, 2006 at 01:27:03PM -0400, Jerry McAllister wrote:
> > 
> > On Tue, April 11, 2006 09:08, Jerry McAllister wrote:
> > >>
> > >> I'm in a bit of a mess here.  I've got an Asus P4C800-E Deluxe
> > >> motherboard with two on-board SATA RAID controllers, an Intel
> > >> MatrixRAID (ICH5R) and Promise Fasttrak (PDC20378).  My BIOS
> > >> allows me to boot from either the Promise or the Intel
> > >> controller.
> > >>
> > >
> > > Well, the install CD is also the fixit CD.  You can try booting
> > > from it and choosing the shell and then trying to run the fdisk
> > > from that environment to replace the MBR.
> > >
> > > I have done that for people who have hosed their MBR on machines
> > > with Ghost - even their XP only, no FreeBSD, systems, using the
> > > FreeBSD fixit, I ran fdisk and replaced the MBR with the FreeBSD
> > > MBR and it worked just fine.
> > >
> > Hi Jerry,
> > 
> > I think the root of my confusion here is the fact that I have two
> > RAID controllers and can boot off either controller.
> > 
> > Does that mean I have two MBR's, one for each controller?  If that's
> > the case and I boot off a CD-ROM, which MBR am I fixing?
> 
> Are both controllers part of the same raid device?   
>
no, as I said in my OP, each controller hosts a RAID1.  The Intel has
two disks for Win, and the FastTrak has two disks dedicated to FreeBSD.

> Anyway, there needs to be an MBR on each bootable device as well as
> the boot files.   I think that holds true for raid setups as well.  
> 
> In addition, the first bootable device that your BIOS sees must have
> an MBR regardless of whether you have 1 or more bootable devices.
> 
> In your case, it sounds like you have two raid devices, one on each
> controller.   You would have to have an MBR on each and it sounds like
> you think you wiped the one on the INTEL controller.   Figure out what
> device name the raid on the INTEL controller comes up as and then
> write the MBR to that.
> 
Thanks for your response.  My follow-up question to you is how would
running a FBSD fdisk command on the Intel controller fix a hosed WinXP
MBR?  Or is an MBR OS agnostic?


-- 
Regards,
Doug