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.
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