From owner-freebsd-questions Tue Jan 15 9:45:38 2002 Delivered-To: freebsd-questions@freebsd.org Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by hub.freebsd.org (Postfix) with ESMTP id CBA8E37B41A for ; Tue, 15 Jan 2002 09:45:31 -0800 (PST) Received: (from dan@localhost) by dan.emsphone.com (8.11.6/8.11.6) id g0FHjUv24277; Tue, 15 Jan 2002 11:45:30 -0600 (CST) (envelope-from dan) Date: Tue, 15 Jan 2002 11:45:29 -0600 From: Dan Nelson To: Joe Abley Cc: freebsd-questions@FreeBSD.ORG Subject: Re: NMBCLUSTERS question Message-ID: <20020115174529.GK46308@dan.emsphone.com> References: <20020115122911.I13795@buffoon.automagic.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020115122911.I13795@buffoon.automagic.org> User-Agent: Mutt/1.3.25i X-OS: FreeBSD 5.0-CURRENT X-message-flag: Outlook Error 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 In the last episode (Jan 15), Joe Abley said: > Every now and then the machine seems to drop off the net for a > little while, and the kernel spits out lots of these: > > fxp0: cluster allocation failed, packet dropped! > m_clalloc failed, consider increase NMBCLUSTERS value > > I don't have an NMBCLUSTERS option set in my kernel conf file. I > see LINT says: > > # Set the size of the mbuf KVM reservation, in clusters. This is scaled > # by approximately 2048 bytes. The system will auto-size the mbuf area > # if this options is not specified or set to 0. > # > options NMBCLUSTERS=1024 > > Does this auto-sizing not work if interfaces are busy? Any > advice as to what I might set NMBCLUSTERS to? "auto-sizing" is a misnomer here. If no value is specified, it is generated from maxusers. It's a constant after that. You actually don't have to rebuild the kernel to override this; you can set it in /boot/loader.conf, and reboot: kern.ipc.nmbclusters="" # Set the number of mbuf clusters Your current max is 2048; try going to 3072 or 4096. -- Dan Nelson dnelson@allantgroup.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message