From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Clements Subject: Re: active/active vs active/passive? Date: Tue, 07 Jun 2005 20:54:36 -0400 Message-ID: <42A641CC.9040905@steeleye.com> References: <1118189397.15459.108.camel@seki.nac.uci.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1118189397.15459.108.camel@seki.nac.uci.edu> Sender: linux-raid-owner@vger.kernel.org To: Dan Stromberg Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Dan Stromberg wrote: > The lecturer at the recent NG storage talk at Usenix in Anaheim, > indicated that it was best to avoid "active/active" and get > "active/passive" instead. > > Does anyone: > > 1) Know what these things mean? In the clustering world, active/active means 2 or more servers are active at a time, either operating on separate data (and thus acting as passive failover partners to each other), or operating on the same data (which requires the use of a cluster filesystem or other similar mechanism to allow coherent simultaneous access to the data). > 2) Know why active/passive might be preferred over active/active? Well, if you're talking about active/passive vs. active/active with a cluster filesystem or such, the active/passive is tons easier to implement and get right. Plus, depending on your application, the added complexity of a cluster filesystem might not actually buy you much more than you could get with, say, NFS or Samba (CIFS). -- Paul