mps0-troubles

[Kenneth D. Merry]

On Fri, Jan 14, 2011 at 01:00:18 +0100, Joachim Tingvold wrote:
> On Thu, Jan 13, 2011, at 21:37:50PM GMT+01:00, Kenneth D. Merry wrote:
> >Did the system recover this time?
> 
> Yes and no. The mv-process is still running, however I can use 'zroot'  
> without issues. I can list some folders on 'storage', but not all --  
> most of them makes my terminal freeze. And as mentioned, a warm reboot  
> doesn't work (I have to physically power-cycle it).

Hmm.

> >Did you see any other messages before the 'out of chain frames'  
> >messages
> >popped up?
> 
> No, not in my last error-log (only boot-entries on the lines above).
> 
> >Try editing sys/dev/mps/mpsvar.h, and change MPS_CHAIN_FRAMES from  
> >1024 to
> >2048 and see if that helps things any.
> >
> >That won't fix the underlying problem, but it may help you avoid  
> >running
> >out of that resource.
> 
> This won't "conflict" with what you've written here[1]? The 9211-8i  
> controller I have, use the SAS2008-chip.

No, this affects the number of buffers available for scatter/gather
entries.  Most commands will just have one physical memory buffer attached,
since system buffer memory is physically contiguous.

It doesn't affect the number of commands the driver sends down to the
chip.

> Would it be possible that low amounts of free memory (<100MB, the  
> system has a total of 4GB) could cause this? (since I'm using ZFS,  
> which relies heavily on memory).

I don't think so.  If anything, I think that this is likely triggered by
a large number of outstanding commands, or perhaps a leak somewhere.  If
it's the former, hopefully this will fix it.  If it's the latter, you'll
eventually run into the problem again.

> [1] <http://www.mail-archive.com/svn-src-head@freebsd.org/msg06214.html>

Ken
-- 
Kenneth Merry
ken at FreeBSD.ORG