Chris Imker wrote:

> Chris Imker wrote:
>
>> I want to install Gentoo 64 on an AMD64X2 system that has two unformatted
>> SATA drives (RAID System wanted). When I enter the BIOS setup, both
>> drives are shown. When I boot the Gentoo Minimal installation CD, there
>> is only /dev/sda. What may be wrong?
>
> Thanks for answers. Yes it seems the controller supports hardware raid. I
> enabled SATA mode=AHCI in the BIOS, now I see both devices.

Normally, if you have a real hardware RAID, the hardware-based set-up tool
will allow you to see all disks and compose a RAID array from them, but to
the operating system, the entire array will be seen only as one disk.

This is how it's supposed to be, as the RAID hardware will manage the
RAID-specific operations, and all the operating system needs to know about
it is how to communicate with the RAID controller.

This said, and as both the posters known as AZ Nomad and pk have stated, you
most likely have a hardware-assisted RAID array, which is the most
prevalent on-board RAID solution offered for SATA.

RAID arrays on these devices are sofware RAID-based but have some hardware
support for certain RAID operations, provided that you use the motherboard
manufacturer's RAID driver, which will in practice always be a binary-only,
proprietary Windows driver. Linux will simply see both hard disks as
individual storage entities and a RAID set-up on these devices must for the
Linux kernel therefore always be set up using the typical /dmraid/ tools,
just as with hard disks attached to any other, non-RAID controllers.

Hope this helps. ;-)

--
Aragorn
(registered GNU/Linux user #223157)