From owner-freebsd-questions Sat Dec 14 15:24:33 2002 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 5D2CE37B404 for ; Sat, 14 Dec 2002 15:24:31 -0800 (PST) Received: from sage-one.net (adsl-65-71-135-137.dsl.crchtx.swbell.net [65.71.135.137]) by mx1.FreeBSD.org (Postfix) with ESMTP id 58BDC43EDA for ; Sat, 14 Dec 2002 15:24:22 -0800 (PST) (envelope-from jackstone@sage-one.net) Received: from sagea (sagea [192.168.0.3]) by sage-one.net (8.11.6/8.11.6) with SMTP id gBENNCd77956; Sat, 14 Dec 2002 17:23:12 -0600 (CST) (envelope-from jackstone@sage-one.net) Message-Id: <3.0.5.32.20021214172311.01244eb8@mail.sage-one.net> X-Sender: jackstone@mail.sage-one.net X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.5 (32) Date: Sat, 14 Dec 2002 17:23:11 -0600 To: Josh Brooks , freebsd-questions@FreeBSD.ORG From: "Jack L. Stone" Subject: Re: NMBCLUSTERS over 4096 dangerous in any way ? In-Reply-To: <20021214143213.E77087-100000@mail.econolodgetulsa.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG At 02:36 PM 12.14.2002 -0800, Josh Brooks wrote: > >Hi, > >I have a firewall that is starting to get a little overworked. I >currently have this line in my kernel config: > >options NMBCLUSTERS=4096 > >and I am starting to hit that limit: > >276/4096/4096 mbuf clusters in use (current/peak/max) > >So, the obvious response is to increase that NMBCLUSTERS value. > >----- > >However, in all the examples and discussion I have seen, I have never seen >anyone discuss raising it above 4096. I have no indication that raising >it to ... say ... 8192 would be dangerous/risky, but I think I should ask >just to make sure. > >The system is a P3-600 with 256 megs physical ram, and 128 megs swap. >This system has no other duties than firewalling. System is running >4.4-RELEASE. > >SO: > >1. any comments on raising NMBCLUSTERS to 8192 ? any other values that >need to be tuned to support that ? > >2. what is the max I could safely raise NMBCLUSTERS to ? > > >thanks! > > Further to my earlier post on this subject and that I chose to use 8192 in my kernel for NMBCLUSTERS, I found this note in my files from some research: ######################################################################## A parameter you may need to change for a busy server, gateway or firewall is NMBCLUSTERS. This controls the size of the kernel mbuf cluster map. On your computer, if you get messages like "mb_map full", you need to increase the value of this parameter. If traffic on a network interface stops for no apparent reason, this may also be a sign that you need to increase the value of NMBCLUSTERS. A reasonable value on the i386 port with most 100Mbps ethernet interfaces (no matter how many the machine has) is 8192. option NMBCLUSTERS=8192 ######################################################################## Best regards, Jack L. Stone, Administrator SageOne Net http://www.sage-one.net jackstone@sage-one.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message