From owner-freebsd-questions@FreeBSD.ORG Wed Jun 23 07:43:51 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 7FF4516A4CE for ; Wed, 23 Jun 2004 07:43:51 +0000 (GMT) Received: from smtp.infracaninophile.co.uk (smtp.infracaninophile.co.uk [81.2.69.218]) by mx1.FreeBSD.org (Postfix) with ESMTP id 394B143D4C for ; Wed, 23 Jun 2004 07:43:50 +0000 (GMT) (envelope-from m.seaman@infracaninophile.co.uk) Received: from happy-idiot-talk.infracaninophile.co.uk (localhost.infracaninophile.co.uk [IPv6:::1])i5N7hHQ8047489 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 23 Jun 2004 08:43:17 +0100 (BST) (envelope-from matthew@happy-idiot-talk.infracaninophile.co.uk) Received: (from matthew@localhost)id i5N7hGkQ047455; Wed, 23 Jun 2004 08:43:16 +0100 (BST) (envelope-from matthew) Date: Wed, 23 Jun 2004 08:43:16 +0100 From: Matthew Seaman To: Robert Huff Message-ID: <20040623074316.GA46661@happy-idiot-talk.infracaninophile.co.uk> Mail-Followup-To: Matthew Seaman , Robert Huff , questions@freebsd.org References: <16600.61068.714211.1647@jerusalem.litteratus.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="BOKacYhQ+x31HxR3" Content-Disposition: inline In-Reply-To: <16600.61068.714211.1647@jerusalem.litteratus.org> User-Agent: Mutt/1.5.6i X-Greylist: Message not sent from an IPv4 address, not delayed by milter-greylist-1.4 (smtp.infracaninophile.co.uk [0.0.0.0]); Wed, 23 Jun 2004 08:43:17 +0100 (BST) X-Virus-Scanned: clamd / ClamAV version devel-20040612, clamav-milter version 0.72a on smtp.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, hits=-4.8 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=2.63 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on happy-idiot-talk.infracaninophile.co.uk cc: questions@freebsd.org Subject: Re: interpreting netstat 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, 23 Jun 2004 07:43:51 -0000 --BOKacYhQ+x31HxR3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 22, 2004 at 10:44:28PM -0400, Robert Huff wrote: >=20 > Poking around the system, I discovered the "m" option to > netstat and got this: >=20 > 261 mbufs in use > 74/17088 mbuf clusters in use (current/max) > 0/4/4528 sfbufs in use (current/peak/max) > 213 KBytes allocated to network > 0 requests for sfbufs denied > 0 requests for sfbufs delayed > 0 requests for I/O initiated by sendfile > 935 calls to protocol drain routines >=20 > ... which would be a lot more useful if I had a reference > standard. Which I can't seen to find. You're OK so long as the current and peak figures are less than the max figure -- mbufs "memory buffers" are a fixed resource, out of which sufficient space to handle network traffic has to be allocated. If you have more traffic than the available space will cope with, then you can't handle all incoming packets, and things will slow right down. On the other hand, if you allocate a lot more space for network traffic, it is forever barred from being used for other purposes. However, for most general purpose systems, just taking the autosized defaults will give you plenty of space to handle incoming traffic without being excessive. You'ld really only have to look at modifying the number of mbufs allocated for a very high traffic server. > This was taken on a system which has had minimal network > traffic for several hours. How would I expect things to change as > load increased? What are the warning signs the network is > approaching saturation? Keep an eye on the mbuf stats if you're worried. So long as the in use numbers don't climb above, say, 80% of the maximum even over a traffic peak, you should be fine. But I doubt you'll see anything like that -- counters on my system show it uses about 2% of capacity. 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 --BOKacYhQ+x31HxR3 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFA2TSUiD657aJF7eIRAtUWAKCyRKxMh1szflKqbGxny1KR57QL2QCeMjpq Cy580d4DEcHF0bSpe56e/H4= =IR36 -----END PGP SIGNATURE----- --BOKacYhQ+x31HxR3--