From owner-freebsd-net@FreeBSD.ORG Mon Feb 10 00:50:42 2014 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8024B605 for ; Mon, 10 Feb 2014 00:50:42 +0000 (UTC) Received: from esa-jnhn.mail.uoguelph.ca (esa-jnhn.mail.uoguelph.ca [131.104.91.44]) by mx1.freebsd.org (Postfix) with ESMTP id 4185B190C for ; Mon, 10 Feb 2014 00:50:41 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: X-IronPort-AV: E=Sophos;i="4.95,814,1384318800"; d="scan'208";a="95135465" Received: from muskoka.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.222]) by esa-jnhn.mail.uoguelph.ca with ESMTP; 09 Feb 2014 19:49:32 -0500 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id EF21FB404B; Sun, 9 Feb 2014 19:49:32 -0500 (EST) Date: Sun, 9 Feb 2014 19:49:32 -0500 (EST) From: Rick Macklem To: aurfalien Message-ID: <1278699658.3088617.1391993372969.JavaMail.root@uoguelph.ca> In-Reply-To: <49357095-33DB-4881-8AC2-847C86E63350@gmail.com> Subject: Re: Terrible NFS performance under 9.2-RELEASE? MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [172.17.91.203] X-Mailer: Zimbra 7.2.1_GA_2790 (ZimbraWebClient - FF3.0 (Win)/7.2.1_GA_2790) Cc: freebsd-net@freebsd.org, Christian Weisgerber X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Feb 2014 00:50:42 -0000 aurfalien wrote: > On Feb 9, 2014, at 10:03 AM, Christian Weisgerber > wrote: > > > Rick Macklem wrote: > > > >> I have a "hunch" that might explain why 64K NFS reads/writes > >> perform > >> poorly for some network environments. > >> A 64K NFS read reply/write request consists of a list of 34 mbufs > >> when > >> passed to TCP via sosend() and a total data length of around > >> 65680bytes. > >> Looking at a couple of drivers (virtio and ixgbe), they seem to > >> expect > >> no more than 32-33 mbufs in a list for a 65535 byte TSO xmit. I > >> think > >> (I don't have anything that does TSO to confirm this) that NFS > >> will pass > >> a list that is longer (34 plus a TCP/IP header). > > > > This may or may not be the same problem: > > > > When I switched my desktop box from FreeBSD 7 to 9, NFS read > > performance from my media server (running OpenBSD) became extremely > > poor. I couldn't even stream a movie any longer. Disabling TSO > > on the nfe(4) interface had no effect. My workaround was to switch > > from a TCP mount to a UDP one. The problem has persisted to > > FreeBSD 10. > > > > I can now report that switching to [rw]size=32768 with a TCP mount > > So either UDP or TCP w/rw sizes of 32K work the same? > Nope. The client limits UDP rsize/wsize to 16K, so you were actually using rsize=16384,wsize=16384 when using UDP. You can "nfsstat -m" on the client to see what the actual "negotiated" mount options are. rick > - aurf > _______________________________________________ > 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" >