From owner-freebsd-questions@FreeBSD.ORG Wed Feb 3 18:55:01 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6621D1065672 for ; Wed, 3 Feb 2010 18:55:01 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from email1.allantgroup.com (email1.emsphone.com [199.67.51.115]) by mx1.freebsd.org (Postfix) with ESMTP id 2342D8FC0A for ; Wed, 3 Feb 2010 18:55:00 +0000 (UTC) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by email1.allantgroup.com (8.14.0/8.14.0) with ESMTP id o13Isv1x089130 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 3 Feb 2010 12:54:57 -0600 (CST) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.4/8.14.3) with ESMTP id o13IsuBt068687 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 3 Feb 2010 12:54:57 -0600 (CST) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.4/8.14.3/Submit) id o13IsujP068676; Wed, 3 Feb 2010 12:54:56 -0600 (CST) (envelope-from dan) Date: Wed, 3 Feb 2010 12:54:56 -0600 From: Dan Nelson To: Rolf Nielsen Message-ID: <20100203185456.GG50360@dan.emsphone.com> References: <4B68EAFD.5070400@lazlarlyricon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B68EAFD.5070400@lazlarlyricon.com> X-OS: FreeBSD 7.2-STABLE User-Agent: Mutt/1.5.20 (2009-06-14) X-Virus-Scanned: clamav-milter 0.95.3 at email1.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0.2 (email1.allantgroup.com [199.67.51.78]); Wed, 03 Feb 2010 12:54:57 -0600 (CST) X-Scanned-By: MIMEDefang 2.45 Cc: FreeBSD Questions Subject: Re: kmem_size / arc_max ratio X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 Feb 2010 18:55:01 -0000 In the last episode (Feb 03), Rolf Nielsen said: > I recently installed more RAM in my computer; increased it from 4GB to > 8GB. Mainly to be able to use a larger arc for zfs. Now my question is, > how much memory does the kernel need apart from the arc? I currently have > kmem_size_max 512MB bigger than arc_max. I haven't run into any problems > so far. I use my computer as desktop only, running WindowMaker and > normally having xconsole, emiclock, firefox with 5+ tabs, thunderbird, > amsn, sunbird, thunar, ktorrent and upto 5 or 6 xterms. > > My loader.conf looks like this: > > vfs.root.mountfrom="zfs:sysroot" > vm.kmem_size_max=5G > vm.kmem_size=5G > vfs.zfs.arc_max=4608M > vm.pmap.pg_ps_enabled=1 > zfs_load="YES" > nvidia_load="YES" vm.kmem_size_max should default to something like 300GB now, so you can remove that line. vm.pmap.pg_ps_enabled defaults to 1 nowadays, too. I have an 8GB system and use these settings: vm.kmem_size=6G vfs.zfs.arc_max=5G -- Dan Nelson dnelson@allantgroup.com