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To: pyunyh@gmail.com
From: Ian FREISLICH <ianf@clue.co.za>
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Date: Tue, 09 Mar 2010 23:55:30 +0200
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Cc: current@freebsd.org
Subject: Re: dev.bce.X.com_no_buffers increasing and packet loss 
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Pyun YongHyeon wrote:
> On Tue, Mar 09, 2010 at 03:31:55PM +0200, Ian FREISLICH wrote:
> > Can you explain the tunables please - I'm guessing it's these:

I think I asked the wrong question.  What is a "Quick BD Chain"?
What relation should this number have to traffic rate.  Is there a
maximum and what are reasonable numbers for setting this to?

I set the RX as high as 512 in 64 quanta but it made little difference
to the interrupt rate.  At times where we experience the packet
loss and com_no_buffers increases, the interrupt rate on between 1
and 3 of the 4 bce interfaces fell from about 3200/s to 130/s.

We're wondering if the switches we're using could be causing this
problem - they're Dell PowerConnect 5448.  I've seen complaints of
random packet loss caused by these switches on the Internet.  We
have some new H3C 5100 series switches which we're planning on
swapping for the Dells tomorrow to see if it makes a difference.

Ian

--
Ian Freislich