From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: multipathd removing DM devices that don't belong to it Date: Mon, 27 Jul 2015 11:12:34 +0200 Message-ID: <55B5F602.1020206@suse.de> References: Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" 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: dm-devel@redhat.com List-Id: dm-devel.ids On 07/24/2015 07:53 PM, Artem Danielov wrote: > Hi, > = > Any chance you guys have looked into this problem? Thank you! > = > = > = > *From:* Artem Danielov > *Sent:* Tuesday, June 16, 2015 15:02 > *To:* 'dm-devel@redhat.com' > *Subject:* multipathd removing DM devices that don't belong to it > = > = > = > Hello, > = > Looking for an advice on whether this is an expected behavior or a bug. > = > device-mapper-multipath-0.4.9-77.el7.x86_64 > = > = > = > When multipathd service starts it will remove any DM devices with > multipath target, _even if the underlying devices are blacklisted_. > = > We are trying to use dmsetup directly to implement custom multipath > management logic separate from multipathd. But unfortunately if > multipathd is present and enabled it removes DM devices with > multipath target that we create. > = Well, hardly surprising. ATM multipathd expects to be the only one creating multipath tables, so of course it would try to 'rectify' the situation. What one could try is to use a different UUID prefix (ie something else than 'mpath') and then teach multipath to ignore all device-mapper devices of type 'multipath' but without the 'mpath' UUID prefix. > = > = > Is this a bug? > = Not as such. Cheers, Hannes -- = Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: F. Imend=F6rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N=FCrnberg)