From owner-freebsd-net Fri May 8 07:09:32 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA26801 for freebsd-net-outgoing; Fri, 8 May 1998 07:09:32 -0700 (PDT) (envelope-from owner-freebsd-net@FreeBSD.ORG) Received: from jingoro.prevmed.sunysb.edu (jingoro.prevmed.sunysb.edu [129.49.123.10]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA26723 for ; Fri, 8 May 1998 07:09:14 -0700 (PDT) (envelope-from cfanning@jingoro.prevmed.sunysb.edu) Received: (from cfanning@localhost) by jingoro.prevmed.sunysb.edu (8.8.8/8.8.5) id JAA12235; Fri, 8 May 1998 09:59:19 GMT From: Chris Fanning Message-Id: <199805080959.JAA12235@jingoro.prevmed.sunysb.edu> Subject: Re: MBUFs and IPFW revisited In-Reply-To: <29428.894629525@cs.ucl.ac.uk> from Panos GEVROS at "May 8, 98 01:12:05 pm" To: P.Gevros@cs.ucl.ac.uk (Panos GEVROS) Date: Fri, 8 May 1998 09:59:19 +0000 (GMT) Cc: dag-erli@ifi.uio.no, freebsd-net@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL31H (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org I'll take a stab at this based on real info and observation... > i 'll take the chance here, > > i've captured instances of netstat -m which reported 99% (even 100%) in use > and occasionally the machine crashed (and then i couldnt tell of course) and i was suspecting that "running out of mbufs" could well be the reason. > > At least that's what i liked to think since we are talking about "sligthly" modified TCP code with several connections opened simultaneoulsy with > large cwnds (around 17K each if i remember well). > > Am i right in assuming : > - "100% in use" will cause a crash ? I believe this will generate a call to the protocol drain routines. This shouldn't crash your box. It may freeze/pause network activity for a few seconds (up to 7ish on mine) until it's done with its thing. (This is based solely on observation.) 100% in use is also assuming that we're talking about 100% of max in use - which is probably the only condition you're likely to see this number anyway. > - the way to increase memory allocated to network is > options "NMBCLUSTERS=XXXX" ? Yes, so long as this number is greater than: #define NMBCLUSTERS (512 + MAXUSERS * 16) Otherwise it could decrease the number of clusters as was pointed out. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message