Re: [2.4.25], [aic79xx-2.0.8] problems with aic79xx on 2.4 (fwd)

[David Haring <david.haring@billboard.cz>]

Hello,

I would recommend reducing TCQ depth too - I have also had
troubles with recent Maxtor Atlas disks / Adaptec / aic79xx
and reducing TCQ depth solved the problem.

Interesting note though - the troubles only showed with Adaptec
controller. When I have replaced the Adaptec aic79xx SCSI card
with Tekram Ultra320 one the system worked without problem.

Ari wrote:
> 
> Hi,
> I've ran into similar problems with the same controller and same disks
> (Maxtor Atlas 10K4 73G WLS, mine are revision DFV0 however).
> After a lot of frustration including changing all related hardware,
> especially the cabling, resultless googling, etc, I found the solution:
> Speeding down the disks does not really help. It works better, but under
> stress load (3 bonnie++ at the same time) they quickly produce lost
> SCB commands, even at 80Mhz.
> What fixed it for me was limiting the Tagged Queuing depth to 16 (in
> kernel config). After my raid5 array worked flawlessly under a 24h
> 3 simultaneous bonnie++ test.
> I've found some hints googling that there might be a firmware problem
> related to this (which should be fixed with the DFV0 version on my
> drives, but obviously is not).
> Anyhow, try to reduce tagged queuing to 16, if that fixes it, it will
> also confirm my findings.

David Haring