From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [BUG] multipath-tools: uuid has become meaningless Date: Wed, 21 Jul 2010 12:44:02 +0200 Message-ID: <4C46CF72.3020101@suse.de> References: <20100719224528.GA23414@us.ibm.com> <1279604124.2841.5.camel@Nokia-N900-42-11> <20100720065410.GA3166@us.ibm.com> <4C454D8A.3020203@suse.de> <20100720220644.GA25337@us.ibm.com> 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: <20100720220644.GA25337@us.ibm.com> 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 Malahal Naineni wrote: > Hannes Reinecke [hare@suse.de] wrote: >> Malahal Naineni wrote: >>> This is where I was heading. I did some investigation and found that we >>> really need to rename to wwid based names before we finally rename to >>> the intended name. So we may actually have two passes just to rename >>> (first to wwid based names and then to actual names). Also the current >>> code doesn't do rename followed by reload even if it is needed. Someone >>> sets friendly name and some other defaults that need reload like path >>> grouping policy etc, we just rename! Probably a bug in itself. > = >> You sure? I would rather rely on device-mapper uuids here. > = > Hannes, I am not sure what you are referring to when you say, "You > sure?" Are you saying if I am sure about this bug? If so, you can see > yourself by swapping couple entries in the bindings file. As I said, > you will notice this bug only when you enable 'user_friendly_names' in > initrd in real life! > = Well, I wanted to inquire about the double renaming thing. But >> So we can use the known naming scheme for the uuid to regenerate the >> wwid; with this we can identify/access the device and we should be able = to >> make do with just one pass. > = > Say, you have "mpath0[uuid0]" and "mpath1[uuid1]" loaded currently. How > can we rename mpath0 to mpath1 and vice-versa? It does require an > intermediate step of renaming to something else, right? = > = is a valid point. So yes, we have to put in a renaming mechanism. So falling back to wwid should work here. Sorry for the noise, you are correct here. Cheers, Hannes -- = 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)