From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id E44F71381F3 for ; Tue, 17 Sep 2013 16:51:23 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id BF002E0C76; Tue, 17 Sep 2013 16:51:12 +0000 (UTC) Received: from mail-we0-f176.google.com (mail-we0-f176.google.com [74.125.82.176]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 9C113E0C50 for ; Tue, 17 Sep 2013 16:51:11 +0000 (UTC) Received: by mail-we0-f176.google.com with SMTP id u56so5253531wes.7 for ; Tue, 17 Sep 2013 09:51:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=MzGhpNBLkzgWId31nwjZvBnPu74lIwkBNFXPJ9dg+v4=; b=MTpYSuAsOoYQN+cr789hYCo5yYYpOlFU8LnfExbjyna4o5LWY6metIEnIE/9ne79HN LqWzOILFzoijgKTbCcrbqu93TMpf+uD+P9AtvTS7W5mQ/MScPtk7PKAEvMX6kIcsMnht sSkvtX7BzgiTSuLd84zHWMcaek5RIto2lOnAyNzhvO2g1KjMGwunIZ1oUZJQRV+aVYMa 2czXC/jMkSFbdNNsnnhLBXGQKmnO2i+phyu/mAlsK6MIf+WH/AVPs5Hs/f6hq2JwaDxQ WlncKalgi6s5yQLdw0Ga7X1dDhvuYDMoUnrZrAHgfW7QT+dfWZQdAm099g21lAJnFSFy 0wbA== X-Received: by 10.194.80.39 with SMTP id o7mr7852097wjx.39.1379436670347; Tue, 17 Sep 2013 09:51:10 -0700 (PDT) Received: from [172.20.0.41] (196-210-126-33.dynamic.isadsl.co.za. [196.210.126.33]) by mx.google.com with ESMTPSA id fz8sm5748386wic.0.1969.12.31.16.00.00 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 17 Sep 2013 09:51:09 -0700 (PDT) Message-ID: <52388782.607@gmail.com> Date: Tue, 17 Sep 2013 18:46:58 +0200 From: Alan McKinnon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130809 Thunderbird/17.0.8 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] {OT} Need a new server References: <5233792D.7040900@orlitzky.com> <3910524.4C314ckqDu@wstn> <52339798.5000409@gmail.com> <523474C4.7080007@orlitzky.com> <52370356.3030204@orlitzky.com> <52384B7A.1030107@orlitzky.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Archives-Salt: 84038f94-6acb-4377-a033-eb54031dd4bf X-Archives-Hash: 48c4c5bf3ac0bcd9c4962f397b133bc4 On 17/09/2013 15:13, Grant wrote: >>> Is multi-mirroring (3-disk RAID1) support without RAID0 common in >>> hardware RAID cards? >> >> Nope. Not at my pay grade, anyway. The only ones I know of are the >> Hewlett-Packard MSA/EVA, but they don't call it plain RAID1. They allow >> you to create virtual disk groups, though, so you can mirror a mirror to >> achieve the same effect. >> >> The only other place I've seen it in real life is Linux's mdraid. > > Thanks Michael. This really pushes me in the ZFS direction. If you need another gentle push, ZFS checksums everything it does as it does it, so it catches data corruption that almost all other systems can't detect. And it doesn't have write holes either. A very good analogy I find is Google, and why Google decided to take the software/hardware route they did (it simplifies down to scalability). Hardware will break and at their scale it will do it three times a day. Google detects and works around this in software. ZFS's approach to how to store stuff on disk in an fs is similar to Google's approach to storing search data across the world. With the same benefit - take the uber-expensive hardware and chuck it. Use regular stuff instead and use it smart. -- Alan McKinnon alan.mckinnon@gmail.com