From owner-freebsd-hackers@FreeBSD.ORG Sat Dec 19 05:47:57 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 88F89106566B for ; Sat, 19 Dec 2009 05:47:56 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-ew0-f226.google.com (mail-ew0-f226.google.com [209.85.219.226]) by mx1.freebsd.org (Postfix) with ESMTP id E39068FC08 for ; Sat, 19 Dec 2009 05:47:55 +0000 (UTC) Received: by ewy26 with SMTP id 26so3128453ewy.3 for ; Fri, 18 Dec 2009 21:47:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:date:message-id:subject :from:to:content-type; bh=ISR4WzYdSzuA2rnVVa3c/aumXAqb6Iejj6SV8+5V7Js=; b=INBtk8rFsMsQd+IXtW60w+Ol3XXGAp8knY57IteYdwEWhQpZngHFlx9MFMsXoGjBtC nGpxJ4VN1+8zdwxPU4z1KtsZBHlHdGC9YUOt7Ushqez5WZJ0Au2QlpGJEuZC0hFeqph4 jfzpDPsVRxVxZx3uT5x8AX/M3Ng00R5blssSA= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=JPNAcsornuWtbTHcEiTvmDKQ9BMpPPMOIjxRtNQhyJ9d3OSl4lBNY56gwc8rbE41CG +6e6PJe7KnLze5VvWwy9xXtX7/DrEqhq1zNLnH6YAzj9l6oQlRMAfNQ8uoDnA10K8amC pBhXawBbE/xHmTww9JW9cwnADszjHLOIiHTqo= MIME-Version: 1.0 Received: by 10.216.90.18 with SMTP id d18mr1787571wef.225.1261201673089; Fri, 18 Dec 2009 21:47:53 -0800 (PST) Date: Sat, 19 Dec 2009 00:47:53 -0500 Message-ID: <5f67a8c40912182147t1adc158ew9fd3d94c4c4c955f@mail.gmail.com> From: Zaphod Beeblebrox To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Subject: scp more perfectly fills the pipe than NFS/TCP X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Dec 2009 05:47:57 -0000 Here's an interesting conundrum. I don't know what's different between the TCP that scp uses from the TCP that NFS uses, but given the same two FreeBSD machines, SCP fills the pipe with packets better. Examine the following graphic: http://www.eicat.ca/~dgilbert/example-mrtg.png The system doing the scp and the NFS server is FreeBSD-7.2-p1. The system receiving the scp and the NFS client is FreeBSD-8.0-p1 The scp transfer is the left hand side of the graph and the NFS transfer is on the right. The NFS is mounted with "-3 -T -b -l -i" and no other options. Files are being moved over NFS with the system "mv" command. The files in each case are large (50 to 500 meg files). The connection is a DSL that terminates on the local lan near the server (I own and run the DSL and the ISP) In either case, the connection is lightly used by only me --- and I'm fairly certain that this isn't another network factor at play.