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List:       freebsd-scsi
Subject:    Re: Invalidating pack messages
From:       Nick Slager <nicks () albury ! net ! au>
Date:       2000-06-28 12:44:08
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Thus spake Thomas Zenker (thz@Lennartz-electronic.de):

> On Tue, Jun 27, 2000 at 03:45:36PM +1000, Nick Slager wrote:
> > In any case, it would appear there is something odd going on that involves
> > write caching. I will turn write caching off again, do a 'make world', and
> > hopefully the confidence factor will start to rise :-)
> 
> Hi, having at least the same symptoms like you, I could isolate
> the problem here to tagged queuing + heavy writes. It never happens
> for reading only, seeks etc. So I can read the whole disk (9G) to
> /dev/null without problems, but writing a big file with iozone or
> dd failes very quickly. I could eliminate the problem by switching of
> tagged queuing, with bad performance loss (write cache is turned off, bad
> this didn't help very much), but it survives buildworlds and writes of 6G files.

So far, I can't kill the thing with write caching disabled. That also has the
least performance hit, so until it fails, I can live with it :-)

Regards,


Nick.

-- 
 From a Sun Microsystems bug report (#4102680):
  "Workaround: don't pound on the mouse like a wild monkey."



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