05-09-2012, 10:03 PM
| | Re: Desktop With Two Hard Drives
> I am not much of a hardware expert...
> I have a desktop with an Intel DQ965GF motherboard. Right now, Ubuntu
> 11.10 is installed on its hard drive.
> The desktop has one SATA hard drive installed. I have this old IDE
> hard drive that I would like to install too and maybe put another Linux
> distribution on it. Therefore the desktop would be dual-booting and
> have two hard drives: one (the primary one) with SATA interface and
> the other one with IDE. (The desktop has both SATA and IDE headers on
> the motherboard.) GRUB2 will be installed on the SATA drive.
> Question 1: Is it possible to have two hard drives with different data
> architectures installed on the same motherboard? Any drawbacks?
> Question 2: How does the system know that the SATA hard drive is the
> one to boot from? SATA drives do not have master/slave jumpers. Is
> there some sort of flag in the BIOS or the two disks' MBR that signals
> which hard drive is the one to boot from after POST?
> Just curious...
Each drive is handled independently.
A lot of the motherboard BIOS I have here, work at two levels
when specifying devices. The top level might be
Net Boot (or other alternative method)
Then, within the Hard Drive area, there is a separate control,
that puts the drives in order
If HDD3 didn't have an MBR with valid signature, then the BIOS might
be able to skip to the next one in the list. And if none were valid,
perhaps it would "fall through" the Hard Drive entry, and you'd see
a PXE netboot status message (spinning cursor).
And all of that is happening at the BIOS level.
If your motherboard is modern enough, it may support a "popup boot
menu". That is an option, that doesn't require "entering" the BIOS,
and allows a temporary boot selection to be made. It looks like
a tiny boot manager. I use that here, when booting from hard
drives, as it saves having to enter the BIOS, and do a
"Save and Exit" to select another disk. On one motherboard,
I press F8 to trigger that. On another motherboard, the
key is F11. Check the first screen full of text in the BIOS,
and look at the bottom line of the screen, to see hints as
to what keys control these functions. (For example, my current
motherboard would say "Press DEL to enter BIOS, or F8 for Popup Boot".
Something along those lines, with a couple defined key presses.)
If your motherboard is set to "Full Screen Logo" mode, and
only a cartoon graphic is present during POST, then the
very first thing you do is enter the BIOS and disable it. And
then you can see all the text I'm referring to. (Once "Full Screen
Logo" is disabled, the POST process will show all its text messages.)