From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ed W Subject: BBU + Writeback Controller suggestions please? Date: Thu, 14 Jun 2012 17:10:59 +0100 Message-ID: <4FDA0D13.9030702@wildgooses.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, repeat of an older question I asked some months back. Looking to add BBU writeback "HBA" to run software raid over the top. So ideally I want either a raid controller which can pretend to be an HBA with 4 individual drives each with writeback cache (and a battery). Or at a pinch I would accept a controller which can offer 2 pairs of RAID-1 with writeback cache and I would run linux raid-0 (or XFS storage groups) over the top - caveat that I would very much desire that if the hardware controller fails I can pull the individual raid-1 drives out and access them from a vanilla motherboard controller? The goal is to be able to safely enable writeback caching on a 4 drive RAID10 (or XFS over raid-1), but if the controller should fail (or even just an urgent need to access the data from a second machine) then I can access the arrays from another machine which doesn't have such a controller. Operating system is a recent linux 3 kernel Can anyone comment on whether such a hardware card exists (seems it's hard to get writeback caching on drives *and* have those drives readable without the same controller present). Currently eyeing up the Areca 1882 8 port unit - thoughts? Thanks for any advice Ed W