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?
Eggert

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?

Nothing, if you have a hardware RAID. You should provide more info about
your motherboard and SATA controller. What's the output of "lspci -v"?

pk 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?
>
> Nothing, if you have a hardware RAID. You should provide more info about
> your motherboard and SATA controller. What's the output of "lspci -v"?

And keep in mind that you can install Gentoo using *any* liveCD, even
knoppix, ubuntu or whatever one you like most (the more recent the better).
Just pick one that you know for sure supports your hardware.

On Wed, 27 Feb 2008 17:31:21 +0100, Chris Imker <chris@nickname.berlin.de> 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?
>Eggert

what is in /proc/scsi/scsi?

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?
> Eggert
Thanks for answers. Yes it seems the controller supports hardware raid. I
enabled SATA mode=AHCI in the BIOS, now I see both devices.
Eggert

On Wed, 27 Feb 2008 20:03:02 +0100, Chris Imker <chris@nickname.berlin.de> 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?
>> Eggert
>Thanks for answers. Yes it seems the controller supports hardware raid. I
>enabled SATA mode=AHCI in the BIOS, now I see both devices.

Just to nitpick, unless you have a $500 motherboard, it won't be hardware
raid. It is just a bios screen of settings and a windows driver to do
raid in software.

Chris Imker wrote:

> Thanks for answers. Yes it seems the controller supports hardware raid. I
> enabled SATA mode=AHCI in the BIOS, now I see both devices.

Now that was the problem. You probably don't have a hardware raid.

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)

Aragorn wrote:

> 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.

Well there's actually the dm* stuff for that kind of fake raids under linux.
However, I wouldnt' advise my worst enemy to use that kludge :-),
especially since pure software raid as provided by linux kernel almost
always works better.

> 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.

ITYM mdraid (yes, I always confuse the two myself)/mdadm or raidtools.

For a good list of which SATA chips are true hw raid and which are fakeraid,
and linux support, these pages might help:

http://tinyurl.com/d6rn7
http://linux-ata.org

Regards

pk wrote:

> Aragorn wrote:
>
>> 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.
>
> Well there's actually the dm* stuff for that kind of fake raids under
> linux. However, I wouldnt' advise my worst enemy to use that kludge :-),
> especially since pure software raid as provided by linux kernel almost
> always works better.

Well, I will admit to my taste being typically more along the expensive side
of things, but a fast, robust, multitasking, multi-user UNIX-style
operating system like GNU/Linux actually deserves true SCSI storage. ;-)

The machine I'm setting up Xen and Gentoo on has an Adaptec 32105 SAS RAID
PCIe controller, with 4 Hitachi UltraStar 147 GB 15k SAS disks, which is a
reliable and fast solution. ;-)

As a sidenote regarding that machine, when I installed the Xen hypervisor
and Xen tools, it took less time for Portage to fetch the sources - I did
an "emerge --sync" first - and then compile them and install them than I am
used to seeing via .rpm-based utilities on binary distributions. :p

I guess the Source is with me, Obi-Wan. :p

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