From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.11.6/8.11.6) with ESMTP id jB20FKV07954 for ; Thu, 1 Dec 2005 19:15:20 -0500 Received: from palrel13.hp.com (palrel13.hp.com [156.153.255.238]) by mx1.redhat.com (8.12.11/8.12.11) with ESMTP id jB20FEJr006018 for ; Thu, 1 Dec 2005 19:15:14 -0500 Received: from smtp2.ptp.hp.com (smtp2.ptp.hp.com [15.1.28.240]) by palrel13.hp.com (Postfix) with ESMTP id D548536FB3 for ; Thu, 1 Dec 2005 16:15:13 -0800 (PST) Received: from [15.244.57.26] (airwolf.cup.hp.com [15.244.57.26]) by smtp2.ptp.hp.com (Postfix) with ESMTP id 72F8C1CCEFC for ; Fri, 2 Dec 2005 00:15:13 +0000 (UTC) Message-ID: <438F9210.3000900@cup.hp.com> Date: Thu, 01 Dec 2005 16:15:12 -0800 From: John DeFranco MIME-Version: 1.0 Subject: Re: [linux-lvm] clvmd interface question References: <437CC1DF.7060306@cup.hp.com> <437D8D72.4050909@redhat.com> In-Reply-To: <437D8D72.4050909@redhat.com> Content-Transfer-Encoding: 7bit Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: LVM general discussion and development Patrick Caulfield wrote: >John DeFranco wrote: > > >>Hi, I'm looking for some information. I'm interested in learning more >>about the clvmd daemon. I've search and found various pieces of info in >>addition to looking at the code. Specifically I looking to for >>information (a spec) on how one might be able to add a new cluster >>manager plugin if you will (if that is even possible). I know that clvmd >>interfaces with a couple of different cluster managers now but I'd like >>to expland this if possible. >> >> > >clvmd supports cman and gulm, it has it's own internal function switch that >determines what to do for each cluster manager. > >To be honest it's not a good API as it was originally only designed to work with >cman and the gulm support was bolted on later - so adding a new cluster manager >might be a bit of work. > >Have a look at the bottom of LVM2/daemons/clvmd/clvmd-cman for the function switch. > >You'll also need to be aware that CMAN provides its own messaging system, which >gulm does not. If your cluster manager provides a messaging system then I >recommend you use it - otherwise you should be able to use the tcp-comms.c file >with clvmd (that gulm support uses). > >Another way, that might be easier, is to patch clvmd with the libcman patch in >head of cluster CVS (cluster/cman/lib/clvmd-libcman.diff) and write a library >for your cluster manager that emulates libcman - that one is a nice simple API >and it will be supported by future versions of cman too. > > > Thanks for the info. I'll be looking into this. -- ========== Cheers -jdf