ZFS "stalls" -- and maybe we should be talking about defaults?

[Karl Denninger]

On 3/4/2013 10:01 PM, Steven Hartland wrote:
> ----- Original Message ----- From: "Karl Denninger" <karl at denninger.net>
>>> Then it happened I thought the machine had wedged, but minutes (not
>>> seconds) later, everything sprung into action again.
>>
>> That's exactly what I can reproduce here; the stalls are anywhere from a
>> few seconds to well north of a half-minute.  It looks like the machine
>> is hung -- but it is not.
>
> Out of interest when this happens for you is syncer using lots of CPU?
>
> If its anything like my stalls you'll need top loaded prior to the fact.
>
>    Regards
>    Steve
Don't know.  But the CPU is getting hammered when it happens because I
am geli-encrypting all my drives and as a consequence it is not at all
uncommon for the load average to be north of 10 when the system is under
heavy I/O load.  System response is fine right up until it stalls.

I'm going to put some effort into trying to isolate exactly what is
going on here in the coming days since I happen to have a spare box in
an identical configuration that I can afford to lock up without
impacting anyone doing real work :-)

-- 
-- Karl Denninger
/The Market Ticker ®/ <http://market-ticker.org>
Cuda Systems LLC