From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: Designing a new prio_callout Date: Fri, 10 Aug 2007 17:07:00 +0200 Message-ID: <46BC7F14.80302@suse.de> References: <46A735E1.4070206@suse.de> <46AD85A5.1060609@suse.de> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids Ethan John wrote: > Is it possible to manually set the priority of a path after a connectio= n has > been established? >=20 > Since we're doing failover-only (only 1 active path at a time), it woul= d be > nice to tell users that they can manually reset priority after a failur= e. > For example, in a configuration with two paths, where one is active and= the > other is passive for two differeent volumes, a failure of one path will > result in all traffic going through the one remaining path. After the s= econd > path comes back up, all traffic will still be written to the first path > (paths are not rebalanced after a failure). >=20 Not necessarily. There is the keyword 'failback', which can be set to=20 IMMEDIATE, causing all paths to fail back to the original path once it comes back. And as you don't actually need to send any commands for facilitate the failover I doubt you'd need to develop your own hardware handler. The existing tweaks should be enough, I think. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: Markus Rex, HRB 16746 (AG N=FCrnberg)