Re: Software raid, booting and bios

[Phil Turmel <philip@turmel.org>]

On 05/20/2011 05:33 AM, Paul van der Vlis wrote:
> 
> The problem is about detected disks with a defect in the MBR.

This is a crucial point.  A BIOS that supports multiple drives in the boot order should skip to the next if the MBR cannot be read.  But the BIOS loses control once the MBR code is executed.  If an error is encountered in later sectors of the bootloader, there's no way to switch to the next drive.  This is also true when the BIOS only supports dissimilar devices in the boot order.

If I had to minimize the chance of this ever biting me, I'd use a CF <==> IDE adapter with a DMA capable CF card, and set it up as my boot device.  And I wouldn't use it for anything but boot.  A quick google turned up this:

http://www.addonics.com/products/flash_memory_reader/adidecf.asp

(Just to show what's out there.)  The embedded boards I use occasionally have the equivalent of this soldered to their motherboards.

The best DMA capable CF cards are usually found in markets that cater to industrial designers or to professional photographers.

HTH,

Phil