From owner-freebsd-stable@FreeBSD.ORG Mon Apr 16 18:10:46 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id A359410657F4 for ; Mon, 16 Apr 2012 18:10:46 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from nk11p00mm-asmtp009.mac.com (nk11p00mm-asmtp009.mac.com [17.158.161.8]) by mx1.freebsd.org (Postfix) with ESMTP id 8655C8FC0A for ; Mon, 16 Apr 2012 18:10:46 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from cswiger1.apple.com (unknown [17.209.4.71]) by nk11p00mm-asmtp009.mac.com (Oracle Communications Messaging Server 7u4-23.01(7.0.4.23.0) 64bit (built Aug 10 2011)) with ESMTPSA id <0M2L00DFN11NLS30@nk11p00mm-asmtp009.mac.com> for freebsd-stable@freebsd.org; Mon, 16 Apr 2012 17:10:36 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.6.7498,1.0.260,0.0.0000 definitions=2012-04-16_04:2012-04-16, 2012-04-16, 1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=6.0.2-1012030000 definitions=main-1204160192 From: Chuck Swiger In-reply-to: <4F8C4F89.7090205@gmail.com> Date: Mon, 16 Apr 2012 10:10:35 -0700 Message-id: References: <4F8C4F89.7090205@gmail.com> To: carlopmart X-Mailer: Apple Mail (2.1084) Cc: freebsd-stable@freebsd.org Subject: Re: ZFS options for FreeBSD 8.3 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Apr 2012 18:10:46 -0000 On Apr 16, 2012, at 9:57 AM, carlopmart wrote: > I have installed FreeBSD 8.3 amd64 release in an ESXi server. Due to some limitations, I can only assign 2GiB of RAM to this virtual machine and I need to use ZFS as filesystem to store some data (MySQL databases). That combination doesn't make much sense, frankly. ZFS is very memory hungry-- I wouldn't want to run it on anything with less than 4GB of RAM, although other folks around here have reported successful setups under 2GB of RAM with some tuning. However, the data integrity benefits of ZFS mostly come from it talking directly to disks in JBOD configuration; if ZFS is just running in a VM and talking to a filesystem image, it loses much of the advantage which it might otherwise provide. You'd almost certainly get better MySQL performance by going with UFSv2 and having the DB use most of the RAM, instead of having it be sucked away by ZFS. Regards, -- -Chuck