mfi "unexpected sense" when using mfip/smartctl

[Scott Long]

On Oct 12, 2010, at 3:15 PM, Kevin Day wrote:
> 
> Hey, SCSI people!
> 
> I'm trying to use smartctl (from smartmontools) with an mfi card. I can kldload mfip, and use smartctl to access SMART data on the member drives fine. The problem is that each time I do so, I get:
> 
> mfi0: 13501 (340232122s/0x0002/info) - Unexpected sense: PD 05(e0x04/s0) Path 50030480006deec4, CDB: 85 06 2c 00 da 00 00 00 00 00 4f 00 c2 00 b0 00, Sense: c/6d/00
> 
> I'm assuming this shows up because the RAID controller isn't expecting the reply to the command that smartctl is sending behind it's back.
> 
> If so, this is pretty harmless, but it looks very very similar to what happens when there's a serious problem with a drive. Is there a way this could be muted, or is this indicating that something is actually not working right? 
> 

You're exactly right about the controller firmware seeing a side effect of running smartctl.  You can cross-ref the sense codes at http://www.t10.org/lists/asc-num.txt if you're interested.  The reported code of "c/6d/00" doesn't make any sense to me, but I guess it's ok.  As long as it's not kicking the array into failover mode, it's harmless.  I think that there is an official way of doing SMART in-band with the controller that avoids this confusion, I'll look into it.  It likely means that smartctl will need learn how to talk to the /dev/mfi0 interface, or mfiutil will need to learn about SMART commands.  Neither option is terribly easy.

Scott