Re: [Testbed-admins] Booting error in Customizing the Generic Image

[Mike Hibler <mike@flux.utah.edu>]

"Real" RAID is good too.  I just assumed you didn't have that.

The gist is that the FreeBSD-based boot programs we use don't know how to
do RAID themselves.  Thus, if you have RAIDed disks, the RAIDing needs to be
transparent to the boot loader; i.e., if the boot loader makes a BIOS read call,
it should be to a logical device and not to one of the underlying components.

You are right, there could be some issue related to the separate RAID
controller BIOS.  When the machine boots via PXE (the network), maybe the
controller BIOS code is not properly loaded or initialized.  Let's see if
the PXE Linux boot works and that might offer further clues.

On Tue, Oct 20, 2009 at 11:07:10PM -0500, Cheng Cui wrote:
> >This is a BIOS supported RAID (aka, "fakeraid") correct?  The
> bootloader
> >uses BIOS calls to read the disk, and if the BIOS was unaware of the
> striping
> >of the disks, bad things would happen.  But again, that would have
> shown up
> >when you booted straight through the MBR boot loader, and that works.
> 
> Sorry, Mike. I may mis-understand your idea about the "fake raid". If
> mentioned BIOS supported RAID, is it the RAID disk controller appeared
> in the BIOS? Please refer to my attached picture about the RAID in BIOS.
> If my understand is right, the BIOS reads the PCI RAID controller info
> ==> give control to the PCI RAID controller ==> then controller loads
> the booting cycles of disks. So maybe the pxeboot gets the wrong info
> from BIOS. But this is just my guess.
> 
> Anyway, thanks for your help. And I am eager to have any good news goes
> on from you and Ryan. Thanks a lot.
> 
> Best Regards,
> 
> Cheng Cui
> . Frey Computing Services Center . Baton Rouge, LA 70803
>