On 9/6/06, Greg Freemyer <greg.freemyer@xxxxxxxxx> wrote:
On 9/5/06, Siddharth Taneja <siddharth.taneja@xxxxxxxxx> wrote:
> Hi,
>
> I have two SATA drives with an ICH6 SATA controller. I would like to know
> that if I were to operate the drives in PATA mode, what would happen if I
> enabled both ide/ata-piix and scsi/piix. I assume the drives would come up
> as both hda/hdb and sda/sdb. Is there a recommendation as to which device
> (or interface) to use?
>
> Also I set the bios settings for the SATA controller to AHCI and the
> ide/ata-piix driver is still able to bring up the drives as hde/hdg. Why is
> that? Shouldn't the ide/ata-piix realise that this is not a mode it
> supports?
>
> Thanks
>
> Siddharth
>
Siddharth,
I don't know the specific answers, but this whole area is in a state of flux.
2.6.16 likely behaves different from 2.6.17 , which is different from
2.6.18, which will be different from 2.6.19.
First, when multiple drivers are available for a single disk
controller, only one of them should be used. Using 2 or more can
cause huge conflicts that could easily destroy data.
Most of the drivers are specifically written to avoid the issue. The
first driver that recognizes a disk controller claims the controller
and no other driver can claim it. In dual functionality controller
like the ICH6, I believe the 2 halves are claimed seperately. ie. The
PATA half can be controlled by drivers/ide and the SATA half can be
controlled by drivers/libata.
That can be difficult to make work smoothly, so there is an ongoing
effort to do the below:
2.6.18 - Greatly improved libata (SATA currently) Error Handling
2.6.19 - Rename drivers/libata to drivers/ata as it is becoming the
main ATA driver
2.6.19 - Add initial support for PATA drives to libata
Thus when 2.6.19 comes out in a few months it will hopefully have the
ability to better handle these dual function controllers. It still
may require proper setup of config due to there still being multiple
drivers that support the same card.
HTH
Greg
--
Greg Freemyer
The Norcross Group
Forensics for the 21st Century
Thanks for your answers Greg. I think I should disable the ide/ata-piix layer and only use my drives in the libata domain as it is becoming the standard in any case.
So you think libata will completely replace the drivers/ide layer? I ask this because I have another platform with two PATA drives and an ICH5 controller. Should I leave ide/piix enabled for that? (for accessing my drives in PATA mode). Or should I use the PATA functionality from the libata layer?
Thanks
Siddharth
