From owner-freebsd-questions@FreeBSD.ORG Wed Oct 27 08:42:29 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A05DA16A4CE for ; Wed, 27 Oct 2004 08:42:29 +0000 (GMT) Received: from smtp.infracaninophile.co.uk (smtp.infracaninophile.co.uk [81.2.69.218]) by mx1.FreeBSD.org (Postfix) with ESMTP id DEFC943D53 for ; Wed, 27 Oct 2004 08:42:28 +0000 (GMT) (envelope-from m.seaman@infracaninophile.co.uk) Received: from happy-idiot-talk.infracaninophile.co.uk (localhost.infracaninophile.co.uk [IPv6:::1])i9R8gOZg073258 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 27 Oct 2004 09:42:24 +0100 (BST) (envelope-from matthew@happy-idiot-talk.infracaninophile.co.uk) Received: (from matthew@localhost)i9R8gOKa073257; Wed, 27 Oct 2004 09:42:24 +0100 (BST) (envelope-from matthew) Date: Wed, 27 Oct 2004 09:42:24 +0100 From: Matthew Seaman To: "Andrew P." Message-ID: <20041027084224.GB72488@happy-idiot-talk.infracaninophile.co.uk> Mail-Followup-To: Matthew Seaman , "Andrew P." , questions@freebsd.org References: <417EA97A.9000206@mail.ru> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="UHN/qo2QbUvPLonB" Content-Disposition: inline In-Reply-To: <417EA97A.9000206@mail.ru> User-Agent: Mutt/1.4.2.1i X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.5.6 (smtp.infracaninophile.co.uk [IPv6:::1]); Wed, 27 Oct 2004 09:42:24 +0100 (BST) X-Virus-Scanned: clamd / ClamAV version devel-20040904, clamav-milter version 0.75l on smtp.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-2.8 required=5.0 tests=ALL_TRUSTED,AWL autolearn=ham version=3.0.1 X-Spam-Checker-Version: SpamAssassin 3.0.1 (2004-10-22) on happy-idiot-talk.infracaninophile.co.uk cc: questions@freebsd.org Subject: Re: Network speed mysteries X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Oct 2004 08:42:29 -0000 --UHN/qo2QbUvPLonB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Oct 26, 2004 at 11:46:02PM +0400, Andrew P. wrote: > Just an hour ago I decided to rebuild the file-server kernel - and it=20 > takes time to build it there, as it's an old Celeron box with little=20 > RAM. By coincidence, some files were being uploaded just when I entered= =20 > "make buildkernel ...". I looked at FileZilla windows, expecting to see= =20 > the speed drop - but WOW! - the speed was at 7Mbytes/s!!! It then=20 > hovered around 6.5-9Mbytes/s while the kernel was being built! I waited= =20 > for some minutes until the kernel was finally built - and the upload=20 > speed dropped back to 2.5-3.5Mb/s. I couldn't believe it - and I still=20 > can't - so I waited and built a kernel once more - with all the same=20 > effects on speed! It's worth to mention, that when I was installing the= =20 > built kernel, the speed didn't change from usual 3Mb/s. >=20 > Please let me know what the heck is going on - or just what you think=20 > about it. So, when the system is under load, the network throughput goes up? That must be a timing issue to do with dealing with ACKs -- perhaps the FreeBSD box just responds too fast for the other end, and loading down the system delays things just long enough to get both ends into sync. What would be useful would be to use tcpdump(1) or ethereal(1) to capture a sample of the network traffic in either situation and bring this up on the freebsd-net@... list. Note that running tcpdump itself might affect the traffic in a similar way -- there's a thread on freebsd-net which you might find interesting, starting here: http://lists.freebsd.org/pipermail/freebsd-net/2004-October/005368.html I you do post to freebsd-net, including the output of 'ifconfig -a' would be a good move. Cheers, Matthew --=20 Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK --UHN/qo2QbUvPLonB Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (FreeBSD) iD8DBQFBf19wiD657aJF7eIRAlTIAJ9ZR4BHK0J22+s+52dQxgWPKgbEUQCgjmsF gUsUnKPhWhdNgc5Gher5YJc= =oFpg -----END PGP SIGNATURE----- --UHN/qo2QbUvPLonB--