From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: HBA Adaptor advice Date: Mon, 23 May 2011 07:44:50 +0800 Message-ID: <4DD99FF2.2030609@fnarfbargle.com> References: <4DD50C89.8060006@wildgooses.com> <20110520020853.GC4759@bitfolk.com> <4DD61948.8050302@wildgooses.com> <4DD6409F.9070904@hardwarefreak.com> <4DD79F4E.7000509@wildgooses.com> <4DD8D1A7.1090803@hardwarefreak.com> <4DD8E0D3.1030905@fnarfbargle.com> <4DD9633E.5000101@hardwarefreak.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4DD9633E.5000101@hardwarefreak.com> Sender: linux-raid-owner@vger.kernel.org To: Stan Hoeppner Cc: Brad Campbell , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 23/05/11 03:25, Stan Hoeppner wrote: > > And that backup array may fail you when you need it most: during a > restore. Search the XFS archives for the horrific tale at University of > California Santa Cruz. The SA lost ~7TB of doctoral student research > data due to multiple WD20EARS drives in his primary storage arrays *and* > his D2D backup array dying in quick succession. IIRC multiple grad > students were forced to attend another semester to redo their > experiments and field work to recreate the lost data, so they could then > submit their theses. So I "googled" that thread, and after I picked my way past all the top rating hits which appear to be you telling people to google that thread I found the real problem. He used WD commodity drives on a "hardware" RAID enclosure that needed TLER. The RAID-5 kicked out 4 drives in a short period of time, so he power cycled it and re-initialised the array and it came up fine, but blank (as it would as he re-initialised it). Sorry Stan, that's not a failure of the drives. He lost the data due to limitations in his RAID configuration and bad management.