Avago LSI SAS 3008 & Intel SSD Timeouts

[Steven Hartland]

On 07/06/2016 20:53, list-news wrote:
> I don't believe the mainboard has any SATA ports.  It does have a PCIe 
> slot IIRC though, and I may be able to rig something up with another 
> LSI adapter I have laying around.  If I can get it to fit and find a 
> way to power the drives.
>
> Although, this seems unlikely unless you are seeing something I'm not?
Nope but your assuming that the backplane doesn't have designed issue, 
and unfortunately that's more common than most people know so my process 
it to always fall back to lowest common denominator and directly attach 
the disks to the controller.
>
> With that last test: If it's the SAS controller, 3 different ones 
> running two different firmware versions are all causing the issue.  If 
> it's the backplane, I have now tested 3 of them as well, two of which 
> I can confirm have different revision numbers.
>
> Errors never appear with tags set to 1 for each drive (effectively 
> eliminating NCQ as I understand it).  My brief understanding is that a 
> higher tag count allows the SAS adapter to send more commands to the 
> drive in parallel, allowing the drive to make the decisions about 
> command ordering.  If that is accurate, and the controller firmware 
> was bad, I assume this would be a far more common bug that would have 
> been fixed already.
>
> On the other hand, if it only happens during heavy SYNCHRONIZE CACHE 
> commands in parallel on certain Intel SSD's and only on controllers 
> (maybe 12gbps?) that can outrun the drive firmware or cause a race 
> condition (my suspicions here).  It seems far more likely this would 
> have gone unnoticed by Intel.

All possible, but discount the easy first. If you have access to 2008 
based controller try that, they have always been solid here not used 
3008 yet.