I have a Asus P5Q motherboard with Intel Q9450 (2.66 Ghz Quad Core),
2GB RAM and 320GB SATA drive.
The board has an ICH10R Southbridge and a Sil5723. The SATA drive is
connected to the ICH10R controller.

I am trying to install Centos / RHEL 4 on this board. Initially the
distro cannot detect the drive and then I changed the SATA controller
to Compatible IDE mode (in the BIOS) and then I could see the drive
and install the distro. However I then notice the IO seems a bit
slow. iostat -k shows a max of only read 2.3MB/s and it seems to run
in PIO mode. DMA is disabled and cannot be turned on by hdparm -d 1.

But when I switch back to Enhanced Mode in the BIOS, the drive is not
detectable.

I tried to upgrade the Kernel to 2.6.9-67 but it still cannot detect
the SATA drive in enhanced mode.

I also tried AHCI mode but again, the kernel does not detect the
drive.

Any suggestion ? I am trying to use this as an Oracle database server
but the IO is very very slow.

Thanks

CK

On Tue, 15 Jul 2008 07:31:19 -0700, cklee1967 wrote:

> I have a Asus P5Q motherboard with Intel Q9450 (2.66 Ghz Quad Core), 2GB
> RAM and 320GB SATA drive.
> The board has an ICH10R Southbridge and a Sil5723. The SATA drive is
> connected to the ICH10R controller.
>
> I am trying to install Centos / RHEL 4 on this board. Initially the
> distro cannot detect the drive and then I changed the SATA controller to
> Compatible IDE mode (in the BIOS) and then I could see the drive and
> install the distro. However I then notice the IO seems a bit slow.
> iostat -k shows a max of only read 2.3MB/s and it seems to run in PIO
> mode. DMA is disabled and cannot be turned on by hdparm -d 1.
>
> But when I switch back to Enhanced Mode in the BIOS, the drive is not
> detectable.
>
> I tried to upgrade the Kernel to 2.6.9-67 but it still cannot detect the
> SATA drive in enhanced mode.
>
> I also tried AHCI mode but again, the kernel does not detect the drive.
>
> Any suggestion ? I am trying to use this as an Oracle database server
> but the IO is very very slow.
>
> Thanks
>
> CK

Install a modern kernel on the system. Download a recent kernel from
kernel.org and build it. The RHEL/CentOS kernels are useless on modern
hardware, RHEL4 uses a .9 kernel which is hopeless, even 5.2 is still
using a .18 which is unusable on Core2 boxes because it lacks the drivers
for the ethernet MACs that are found on most Core2 motherboards. I have a
2.6.23.17 kernel on my CentOS5 system which works fine. I picked a .23
because VMware Server 2.0 beta2 has trouble with kernels later
than .23.x, I haven't checked to see if Server 2.0RC1 has fixed that
issue, it may have.

On Tue, 15 Jul 2008, cklee1967@gmail.com wrote:

> I have a Asus P5Q motherboard with Intel Q9450 (2.66 Ghz Quad Core),
> 2GB RAM and 320GB SATA drive.
> The board has an ICH10R Southbridge and a Sil5723. The SATA drive is
> connected to the ICH10R controller.
>
> I am trying to install Centos / RHEL 4 on this board. Initially the
> distro cannot detect the drive and then I changed the SATA controller
> to Compatible IDE mode (in the BIOS) and then I could see the drive
> and install the distro. However I then notice the IO seems a bit
> slow. iostat -k shows a max of only read 2.3MB/s and it seems to run
> in PIO mode. DMA is disabled and cannot be turned on by hdparm -d 1.
>
> But when I switch back to Enhanced Mode in the BIOS, the drive is not
> detectable.
>
> I tried to upgrade the Kernel to 2.6.9-67 but it still cannot detect
> the SATA drive in enhanced mode.
>
> I also tried AHCI mode but again, the kernel does not detect the
> drive.

You need to edit the file /etc/modprobe.conf to add the line:
alias scsi_hostadapter ahci

Then you need to recreate the initrd file (/boot/initrd-2.6.9-67.img or
something similar -- the exact name will be in /etc/grub.conf). You create
this file with the command "mkinitrd".

Then set your disks in AHCI mode again and reboot.

You can have multiple lines in /etc/modprobe.conf for different adapters,
so you could also have:

alias scsi_hostadapter1 xxxx

where "xxxx' is the name of the kernel module (minus the ".o") that
provides support for your disk controller. However, looking at this page:
http://gentoo-wiki.com/Asus_P5Q-E
it appears that using AHCI is most likely to be successful.

OK, I found that (by turning off the quiet and rhgb option on the
kernel command lines) that on 2.6.9-67, the ahci driver
actually picks up the SATA drives attached to the ICH10R controller.
So I moved all the partitions out to another external
drive before I reformatting the SATA disk (for some reason, when I
installed it using COMPATIBLE mode and LVM2, VolGroup00
was not recognize when using the ahci driver). Then I copied back the
partition from the external drive (without LVM2) and
installed grub on it again. It now works and I can get roughly 30MB/s
read/write throughput.

On another note, the motherboard also has a Marvell 6121 with a Sil
5723 behind it with 2 SATA ports. So I can setup
something called SuperSpeed which seems like "disk striping" in
hardware. It will even boot on the drives using a more
recent kernel (ubuntu 8.04) but it requires pata_marvell to work which
is missing from 2.6.9-67.

Thanks to whoever for the pointer.