From owner-freebsd-fs@FreeBSD.ORG Tue Oct 4 23:30:19 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 85534106566C for ; Tue, 4 Oct 2011 23:30:19 +0000 (UTC) (envelope-from ari@ish.com.au) Received: from fish.ish.com.au (eth5921.nsw.adsl.internode.on.net [59.167.240.32]) by mx1.freebsd.org (Postfix) with ESMTP id 433D48FC12 for ; Tue, 4 Oct 2011 23:30:18 +0000 (UTC) Received: from ip-136.ish.com.au ([203.29.62.136]:53515 helo=Aris-MacBook-Pro.local) by fish.ish.com.au with esmtpsa (TLSv1:CAMELLIA256-SHA:256) (Exim 4.76) (envelope-from ) id 1RBERC-0003cf-0x; Wed, 05 Oct 2011 10:30:14 +1100 X-CTCH-RefID: str=0001.0A150204.4E8B9706.00DD:SCFSTAT15613948, ss=1, re=-4.000, fgs=0 Message-ID: <4E8B9703.4070303@ish.com.au> Date: Wed, 05 Oct 2011 10:30:11 +1100 From: Aristedes Maniatis User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:7.0) Gecko/20110916 Thunderbird/7.0 MIME-Version: 1.0 To: Andriy Gapon References: <4E8A8740.100@ish.com.au> <4E8B08FA.1020900@FreeBSD.org> In-Reply-To: <4E8B08FA.1020900@FreeBSD.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-fs@FreeBSD.org Subject: Re: vm.kmem_size_scale recommendation for ZFS X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 04 Oct 2011 23:30:19 -0000 On 5/10/11 12:24 AM, Andriy Gapon wrote: > on 04/10/2011 07:10 Aristedes Maniatis said the following: >> B. vm.kmem_size_scale=0.66 > > This parameter is integer. Ah, of course. Would it then be the recommendation that kmem be set manually to 150% of physical memory, or should it normally be left to its default in a machine with a medium amount of RAM (24Gb) and heavy usage of ZFS? I've googled but I just can't understand what the purpose would be of setting kmem to greater than physical memory. But if it helps... Ari -- --------------------------> Aristedes Maniatis ish http://www.ish.com.au Level 1, 30 Wilson Street Newtown 2042 Australia phone +61 2 9550 5001 fax +61 2 9550 4001 GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A