From owner-freebsd-net@FreeBSD.ORG Sun Jan 26 03:19:24 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 576EFCC4; Sun, 26 Jan 2014 03:19:24 +0000 (UTC) Received: from esa-annu.net.uoguelph.ca (esa-annu.mail.uoguelph.ca [131.104.91.36]) by mx1.freebsd.org (Postfix) with ESMTP id EA2CF11C8; Sun, 26 Jan 2014 03:19:23 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AqQEAHF95FKDaFve/2dsb2JhbABag0RWgn25AU+BH3SCJQEBAQMBAQEBICsgCwUWGAICDRkCKQEJJgYIBwQBHASHXAgNq1+cLheBKY0TAQEbNAeCb4FJBIlIjAyEBZBsg0seMYEEOQ X-IronPort-AV: E=Sophos;i="4.95,721,1384318800"; d="scan'208";a="90491411" Received: from muskoka.cs.uoguelph.ca (HELO zcs3.mail.uoguelph.ca) ([131.104.91.222]) by esa-annu.net.uoguelph.ca with ESMTP; 25 Jan 2014 22:19:23 -0500 Received: from zcs3.mail.uoguelph.ca (localhost.localdomain [127.0.0.1]) by zcs3.mail.uoguelph.ca (Postfix) with ESMTP id 15FD7B4054; Sat, 25 Jan 2014 22:19:23 -0500 (EST) Date: Sat, 25 Jan 2014 22:19:23 -0500 (EST) From: Rick Macklem To: Garrett Wollman Message-ID: <688905116.16333139.1390706363082.JavaMail.root@uoguelph.ca> In-Reply-To: <21220.32074.958702.595502@hergotha.csail.mit.edu> 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: [172.17.91.209] X-Mailer: Zimbra 7.2.1_GA_2790 (ZimbraWebClient - FF3.0 (Win)/7.2.1_GA_2790) Cc: freebsd-fs@freebsd.org, freebsd-net@freebsd.org 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: Sun, 26 Jan 2014 03:19:24 -0000 Garrett Wollman wrote: > < said: > > > Have you tried increasing readahead by any chance? I think the > > default > > is 1, which means the client will make 2 read requests and then > > wait for > > those replies before doing any more reads. Since you have fast > > links, > > maybe the 2 * 64K reads isn't enough to keep the pipe filled? (This > > depends on latency, which you didn't mention.) > > -o readahead=4 nearly doubles the speed, to a bit over 5 Gbit/s. > And "-o readahead=8" is slower or faster? (I think you can go up to at least 16, but I can't remember the upper bound. It's in one of the .h files.;-) > Oddly, when I unmount the filesystem, the test client sometimes > freezes for 15-30 seconds. Since I'm not on the console I can't tell > what it's doing when this happens. > Hmm, no idea. Maybe it takes a while to throw away all the buffer cache blocks? I run such small systems by to-days standards, I wouldn't see a delay that "might" occur for a large buffer cache. At least a little progress, rick > -GAWollman > > _______________________________________________ > 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" >