Re: Corrupt data - RAID sata_sil 3114 chip

[Bernd Schubert <bs@q-leap.de>]

[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*).


Cheers,
Bernd