Date: Mon, 13 Aug 2007 20:58:22 -0400 From: "Isaac Kohen" <ik1024@gmail.com> To: "Lawrence Stewart" <lstewart@room52.net> Cc: freebsd-net@freebsd.org, Kevin Oberman <oberman@es.net> Subject: Re: Very high wide area TCP tuning Message-ID: <7feb82f40708131758t194e93f1k371642524991eb71@mail.gmail.com> In-Reply-To: <46C0EEB6.6010702@room52.net> References: <20070813183426.C196D45045@ptavv.es.net> <46C0EEB6.6010702@room52.net>
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I've sent several messages to "freebsd-net-unsubscribe@freebsd.org" and I'm still receiving messages. How do I stop this? On 8/13/07, Lawrence Stewart <lstewart@room52.net> wrote: > > Hi Kevin, > > Kevin Oberman wrote: > > I am attempting to use a FreeBSD box with either a Myricom or Chelsio > > 10GE card to generate very large TCP streams over cross-country > > links. The RTT for the test path is 94 ms. It is dedicated to my testing > > at this time, so I have no contention other than a few KB of routing > > updates. > > > > Clearly, I need a very large window...about 120 MB, but I am unsure how > > FreeBSD will handle this. (Unless I do other things, I suspect it will > > not be pretty.) I imagine I will need a large kvm space, at the least, > > but are there any other sysctls that are likely to need adjusting to > > make this all work? IS it likely to work better on a amd64 system than a > > i386? > > > > Any suggestions would be appreciated. > > > > We recently wrote a small technical report that covers some of the > issues related to FreeBSD network tuning for some TCP research we've > been doing. > > The report's title is "Tuning and Testing the FreeBSD 6 TCP Stack" and > you can grab it from here: > http://caia.swin.edu.au/reports/070717B/CAIA-TR-070717B.pdf > > We didn't tune for 10GB speeds, but I imagine the principles should all > still apply. As you correctly point out, you'll also probably want to > raise the allowable kernel mem size using the "vm.kmem_size" and > "vm.kmem_size_max" sysctls to avoid any random kernel panics. We used a > kmem size of 500MB which worked flawlessly with our GigE multiflow tests > and left us plenty of room to move. This is something you might have to > use a bit of trial and error to figure out though to ensure you get > something stable. And of course you're going to want to control the > number of flows active at one time based on your kmem setting and > hardware constraints... > > Cheers, > Lawrence > > http://caia.swin.edu.au > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" >
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