From owner-freebsd-current@FreeBSD.ORG Wed Nov 19 09:40:31 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F265A1065679; Wed, 19 Nov 2008 09:40:31 +0000 (UTC) (envelope-from ler@lerctr.org) Received: from thebighonker.lerctr.org (thebighonker.lerctr.org [192.147.25.65]) by mx1.freebsd.org (Postfix) with ESMTP id C69258FC2C; Wed, 19 Nov 2008 09:40:31 +0000 (UTC) (envelope-from ler@lerctr.org) Received: from 76-205-169-61.lightspeed.austtx.sbcglobal.net ([76.205.169.61]:10607 helo=borg) by thebighonker.lerctr.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1L2jJG-000Nf4-6R; Wed, 19 Nov 2008 03:25:20 -0600 Date: Wed, 19 Nov 2008 03:25:15 -0600 (CST) From: Larry Rosenman Sender: ler@borg To: Jeremy Chadwick In-Reply-To: <20081119090307.GA81236@icarus.home.lan> Message-ID: References: <20081117205526.GC1733@garage.freebsd.pl> <8ECD400F-BFE3-4E31-94F0-39AF5F44FDAC@gmail.com> <20081119090307.GA81236@icarus.home.lan> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Spam-Score: -2.3 (--) X-LERCTR-Spam-Score: -2.3 (--) X-Spam-Report: SpamScore (-2.3/5.0) ALL_TRUSTED=-1.8, BAYES_00=-2.599, SARE_SUB_OBFU_OTHER=0.135, TVD_RCVD_IP=1.931, TW_ZF=0.077 X-LERCTR-Spam-Report: SpamScore (-2.3/5.0) ALL_TRUSTED=-1.8, BAYES_00=-2.599, SARE_SUB_OBFU_OTHER=0.135, TVD_RCVD_IP=1.931, TW_ZF=0.077 DomainKey-Status: no signature Cc: Nikolay Denev , freebsd-current@freebsd.org Subject: Re: HEADS UP: New ZFS in the tree. X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Nov 2008 09:40:32 -0000 On Wed, 19 Nov 2008, Jeremy Chadwick wrote: > > Since this is CURRENT, you should be able to increase the kmem_size > and kmem_size_max entries to something larger than 1536M, especially > since the box has 4GB of RAM. (You shouldn't do this on RELENG_7). > > You might also consider disabling prefetch; there are reports of > peoples' boxes locking up hard (requiring a hard reset) when prefetch > is enabled. Others (like myself) just see "better overall system > responsiveness" when prefetch is disabled. Just as a note, with a -CURRENT from shortly after the ZFS upgrade, the vm.kmem* tuneables, without ANY override on my 4G amd64 box: vm.kmem_size_scale: 3 vm.kmem_size_max: 4509713203 vm.kmem_size_min: 0 vm.kmem_size: 1381195776 this is with a 2T zfs array, if that matters. -- Larry Rosenman http://www.lerctr.org/~ler Phone: +1 512-248-2683 E-Mail: ler@lerctr.org US Mail: 430 Valona Loop, Round Rock, TX 78681-3893