From owner-freebsd-stable Mon Apr 2 16:18:47 2001 Delivered-To: freebsd-stable@freebsd.org Received: from bitbucket.extern.uniface.nl (bitbucket.extern.uniface.nl [193.78.88.139]) by hub.freebsd.org (Postfix) with ESMTP id 847AB37B728 for ; Mon, 2 Apr 2001 16:18:44 -0700 (PDT) (envelope-from driehuis@playbeing.org) Received: from bh2.nl.compuware.com (unknown [172.16.17.82]) by bitbucket.extern.uniface.nl (Postfix) with ESMTP id 568AE828A; Tue, 3 Apr 2001 01:18:43 +0200 (CEST) Received: from trashcan.nl.compuware.com ([172.16.16.52]) by bh2.nl.compuware.com with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2650.21) id 21272RYD; Tue, 3 Apr 2001 01:18:43 +0200 Received: from c1111.nl.compuware.com (c1111.nl.compuware.com [172.16.16.36]) by trashcan.nl.compuware.com (Postfix) with ESMTP id EB7C2145A4; Tue, 3 Apr 2001 01:18:42 +0200 (CEST) Date: Tue, 3 Apr 2001 01:18:42 +0200 (CEST) From: Bert Driehuis X-Sender: bertd@c1111.nl.compuware.com To: "Jason T. Luttgens" Cc: freebsd-stable@FreeBSD.ORG Subject: RE: Network performance question In-Reply-To: <000001c0bbc9$cc97b990$0200010a@lucky> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 2 Apr 2001, Jason T. Luttgens wrote: > However - I noticed something while testing. Linux 2.4.3 did not access the > drive as much as FreeBSD was. I guess Linux is caching the file more or > something...who knows. So I re-performed the tests with output going to > /dev/null and looking at the tcpdump and interface counters (I know, it's > not the best way, but at this point I was thinking it's the disk I/O that's > causing the drops/loss). You could try enabling softupdates if you haven't done so yet. For benchmarking purposes, you could also try async mount (but note that async can screw up your disk real bad in case of a system crash). I would not expect either to have much effect if the machine is otherwise quiescent, but if you are being hit because of any synchronous activity going on it would be nice if this could be eliminated from the equation. Note that you really are entering a grey area here -- it may well be that the respective kernels have different priorities or strategies that have little to do with Ethernet performance, e.g. FreeBSD's insistence (by default) that file systems remain consistent in case of a system crash might cause some packets to be lost in this flat out. worst case scenario. It is unlikely that you will prove what happens unless you stumble upon something that eliminates the difference. Cheers, -- Bert -- Bert Driehuis -- driehuis@playbeing.org -- +31-20-3116119 If the only tool you've got is an axe, every problem looks like fun! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message