Re: Corrupt data - RAID sata_sil 3114 chip

[Robert Hancock <hancockrwd@gmail.com>]

On 01/29/2010 10:13 AM, Ulli.Brennenstuhl wrote:
> The last message of this discussion is more than one year old, but still
> there was no solution to this problem.
>
> I recently encountered the same problem that a raid created with mdadm
> consisting of three SAMSUNG HD154UI sata harddisks had random errors and
> mdadm --examine would randomly report that checksums are wrong/correct.
>
> The sata controller with the SIL 3114 chipset runs on an old Epox 8K3A
> board with a VIA KT133 chipset. I noticed that placing the controller in
> another pci slot would change the results of mdadm --examine.
> While in one slot it was the checksums were randomly changing between
> correct and wrong in another slot it was always displayed as wrong.
>
> After deactivating every single bios option that somehow optimizes the
> pci bus the problem seems to be gone. After some more testing I could
> narrow the problem down to the option "PCI Master 0 WS Write", which
> controls if requests to the pci bus are executed immediately (with zero
> wait states) or if every write request will be delayed by one wait state.
>
> Obviously this reduces the performance. I didn't perform tests but the
> resync speed of the raid dropped from ~ 28mb/s to ~ 17mb/s.
>
> I hope this also solves the problems for other people and it would be
> interesting if any change to the driver would allow to reenable the "PCI
> Master 0 WS Write" option.

I don't imagine there's anything the driver's likely to be able to do to 
avoid it. That sounds like a definite chipset bug. The PCI interface on 
older VIA chipsets was pretty notorious for them.