From owner-freebsd-performance@FreeBSD.ORG Fri Aug 17 00:47:19 2012 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B2FD81065672 for ; Fri, 17 Aug 2012 00:47:19 +0000 (UTC) (envelope-from gezeala@gmail.com) Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by mx1.freebsd.org (Postfix) with ESMTP id 8A5478FC12 for ; Fri, 17 Aug 2012 00:47:19 +0000 (UTC) Received: by pbbrp2 with SMTP id rp2so2598789pbb.13 for ; Thu, 16 Aug 2012 17:47:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:from:date:message-id:subject:to:content-type; bh=FVgNNgNp8DS++1hSlVA+Sk+iOpvqFM6b7r0cxcm2TCU=; b=AQmZ4v2McMkBFcg5bR14ETEbZu3nSbyZJAt/V1M7U1eK9WgFUtuYrODP4xk1Lr9q+W axUzWC+UvOjSvLmOz48waxpm4jZNavXy5qDh8pKY2BV/Q7Oq2smbyD01vMFiqTwLVXtl YydX9Qe7osINTAgvVZGf+CZ4pLkciioOY7Y6iXGfkeCvykXyOq/CvScmWTwTxt4dbpGd LKVsudxrCZKioAQg20ZOWrg4Q+A7IikhX0RI5S9Edjo1dSaIFNAOiXKkZ21w56lSm36q 3MbF5RQZFHOYc4gnpn4BaXA7NZIxAv9VFgwOc9M5EPMc1Nfkn2YzHeF42tEgMiFInCvB 2h7g== Received: by 10.68.230.232 with SMTP id tb8mr7290117pbc.19.1345164438590; Thu, 16 Aug 2012 17:47:18 -0700 (PDT) MIME-Version: 1.0 Received: by 10.68.190.71 with HTTP; Thu, 16 Aug 2012 17:46:58 -0700 (PDT) From: =?ISO-8859-1?Q?Gezeala_M=2E_Bacu=F1o_II?= Date: Thu, 16 Aug 2012 17:46:58 -0700 Message-ID: To: freebsd-performance@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Subject: vm.kmem_size_max and vm.kmem_size capped at 329853485875 (~307GB) X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Aug 2012 00:47:19 -0000 Hello fellow listers, On a server with 512GB RAM it appears that vm.kmem_size_max is not being auto-tuned to use >329853485875 (~307GB). On this machine vm.kmem_size is equal to vm.kmem_size_max # from sysctl vm.kmem_size_max: 329853485875 vm.kmem_size: 329853485875 On a machine with 1GB of RAM, I have successfully set vm.kmem_size_max to 330GB and vm.kmem_size automatically adjusts to 1GB even if I manually set it in /boot/loader.conf. But on the machine with 512GB of RAM it just resets. For the machine to boot, we need to go to the loader prompt and issue: OK set vm.kmem_size_max="300G" OK boot On all PCBSD (8,9) or FreeBSD (8.1,8.2,9) machines we have, vm.kmem_size_max is always set to 329853485875. How can I increase vm.kmem_size_max to use at least 500GB? And how is 329853485875 determined (formula)? I need to increase vm.kmem_size_max and vm.kmem_size so I can set vfs.zfs.arc_max (ZFS ARC) to use say 490GB. I'm browsing thru the source code at http://fxr.watson.org/fxr/search?v=FREEBSD9&string=vm.kmem_size_max and I'm still trying to make sense of how vm.kmem_size_max is computed. I have posted the same topic on forums.freebsd.org but I'm not getting any recommendations. Please see the link for additional details: http://forums.freebsd.org/showthread.php?t=33977 TIA! -- regards