From owner-freebsd-questions@FreeBSD.ORG Tue Jul 10 10:39:59 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9CD69106567A for ; Tue, 10 Jul 2012 10:39:59 +0000 (UTC) (envelope-from b.smeelen@ose.nl) Received: from mail.ose.nl (mail.ose.nl [212.178.134.164]) by mx1.freebsd.org (Postfix) with ESMTP id 328908FC17 for ; Tue, 10 Jul 2012 10:39:59 +0000 (UTC) X-Footer: b3NlLm5s Received: from localhost ([127.0.0.1]) by mail.ose.nl (using TLSv1/SSLv3 with cipher AES256-SHA (256 bits)) for freebsd-questions@freebsd.org; Tue, 10 Jul 2012 12:39:56 +0200 Message-ID: <4FFC0665.6040109@ose.nl> Date: Tue, 10 Jul 2012 12:39:33 +0200 From: Bas Smeelen User-Agent: Mozilla/5.0 (X11; Linux i686; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <4FFBEE6E.6000906@ulb.ac.be> <4FFC013A.3040903@ose.nl> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: FreeBSD 9.0 & LSI MegaRAID SATA problem X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 10 Jul 2012 10:39:59 -0000 On 07/10/2012 12:26 PM, Wojciech Puchar wrote: >> >> That's clear to me. >> These "hardware" raid controllers are not very reliable because they are >> indeed not real hardware raid controllers, but software based. >> Maybe for desktop usage it's ok/ good enough? > > precise what is "desktop" usage is. Here at work we just use non raided disks for workstations which run linux. The home directories are on nfs, so when a disk fails it's replaced very fast by doing a basic install on a new disk or just replacing the disk by a preinstalled disk laying on the shelf here. > i don't see a reason for doing mirroring for home use. Me neither, just keep back-ups of important data on a different place/device > >> It is better to use the operating systems raid capability linke gmirror >> instead. >> > always. > >> Of course real hardware raid controllers with cache and battery backed >> are a different thing and very reliable. > > if you have workload where battery backed cache will actually improve > things (heavy fsync usage) then yes. otherwise no. > > i've seen many of them, older, newer, and with same disks i always got at > least same performance with FreeBSD software solution. > > Not talking about RAID5 of which i am not interested at all - there is no > reason trading performance for available space nowadays with 2-3TB disks. I have never tries the FreeBSD raid solution as we always have servers with from past to now acc, amr and mfi controllers with raid1 and raid5 in the past mostly used for databases and perl cgi based web applications. Disclaimer: http://www.ose.nl/email