Re: Corrupt data - RAID sata_sil 3114 chip

[Robert Hancock <hancockr@shaw.ca>]

Bernd Schubert wrote:
> [sorry sent again, since Robert dropped all mailing list CCs and I didn't 
> notice first]
> 
> On Sat, Jan 03, 2009 at 12:31:12PM -0600, Robert Hancock wrote:
>> Bernd Schubert wrote:
>>> On Sat, Jan 03, 2009 at 01:39:36PM +0000, Alan Cox wrote:
>>>> On Fri, 2 Jan 2009 22:30:07 +0100
>>>> Bernd Schubert <bs@q-leap.de> wrote:
>>>>
>>>>> Hello Bengt,
>>>>>
>>>>> sil3114 is known to cause data corruption with some disks. 
>>>> News to me. There are a few people with lots of SI and other devices
>>> No no, you just forgot about it, since you even reviewed the patches ;)
>>>
>>> http://lkml.org/lkml/2007/10/11/137
>> And Jeff explained why they were not merged:
>>
>> http://lkml.org/lkml/2007/10/11/166
>>
>> All the patch does is try to reduce the speed impact of the workaround.  
>> But as was pointed out, they don't reliably solve the problem the  
>> workaround is trying to fix, and besides, the workaround is already not  
>> applied to SiI3114 at all, as it is apparently not applicable on that  
>> controller (only 3112).
> 
> Well, do they reliable solve the problem in our case (before taking the patch
> into production I run a checksum tests for about 2 weeks). Anyway, I entirely
> understand the patches didn't get accepted. 
> 
> But now more than a year has passed again without doing anything
> about it and actually this is what I strongly criticize. Most people don't
> know about issues like that and don't run file checksum tests as I now always
> do before taking a disk into production. So users are exposed to known
> data corruption problems without even being warned about it. Usually
> even backups don't help, since one creates a backup of the corrupted data.
> 
> So IMHO, the driver should be deactived for sil3114 until a real solution is 
> found. And it only should be possible to force activate it by a kernel flag, 
> which then also would print a huuuge warning about possible data corruption 
> (unfortunately most distributions disables inital kernel messages *grumble*).

If the corruption was happening on all such controllers then people 
would have been complaining in droves and something would have been 
done. It seems much more likely that in this case the problem is some 
kind of hardware fault or combination of hardware which is causing the 
problem. Unfortunately these kind of not-easily-reproducible issues tend 
to be very hard to track down.