From owner-freebsd-questions@FreeBSD.ORG Tue Jan 29 10:32:01 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 40564206 for ; Tue, 29 Jan 2013 10:32:01 +0000 (UTC) (envelope-from matrix@itlegion.ru) Received: from corpmail.itlegion.ru (corpmail.itlegion.ru [84.21.226.211]) by mx1.freebsd.org (Postfix) with SMTP id 5B4AAE17 for ; Tue, 29 Jan 2013 10:32:00 +0000 (UTC) Received: (qmail 10080 invoked from network); 29 Jan 2013 14:31:55 +0400 Received: from localhost-artem.itlegion.ru (HELO ?192.168.0.12?) (192.168.0.12) by 84.21.226.211 with SMTP; 29 Jan 2013 14:31:55 +0400 Message-ID: <5107A500.4030902@itlegion.ru> Date: Tue, 29 Jan 2013 14:31:28 +0400 From: Artem Kuchin Organization: IT Legion User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 CC: freebsd-questions@freebsd.org Subject: Re: Software raid VS hardware raid References: <5106E301.4070707@itlegion.ru> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Jan 2013 10:32:01 -0000 29.01.2013 11:54, Michael Powell: > Artem Kuchin wrote: > > > I guess what I'm trying to point out is that low performance wrt software > RAID will stem from other things besides just simply consuming a few CPU > cycles. Today's CPUs have the cycles to spare. I've been using gmirror for > RAID 1 mirrors for a few years now and am happy with this. I have had a few > old drives die and the servers stayed up and online. This allowed me to > defer the actual drive replacement and not have to drop everything and fight > fire. > Thank you everyone for replying. I realize that many other things affect the performance, not only the CPU power. For example, disk IO kernel multithreading is one of the things. But i guess in FBSD 9 it is more or less solved. The server is going to be a web server with many sites and with mysql running on it. Nothing really really heavy. Currently with run all this on our own server with 8 cores and 16GB ram and 3ware raid1 and cpu load is about 5% :) Everything is quick and responsive. I hope to see the same on a software raid. I really don't want to deploy ZFS on a new server where all these site need to migrate because i am kind of "don't fix it if it is not broken" kind of guy. UFS+journaling+softupdates served us well for years and snapshots are available on ufs too. My other concern is what happens when one drive goes down if we use gmirror? Is it completelly transparent and bad drive can be hot swapped while server is running and rebuild started? I am thinking now about gpt+gmirror (including boot and swap) Artem