23.12.2010 14:14, Andrew Beekhof wrote: > On Thu, Dec 23, 2010 at 10:41 AM, Vladislav Bogdanov > <bub...@hoster-ok.com> wrote: >> Hi Andrew, >> >> It was a big surprise for me to see all pacemaker-specific bits removed >> from dlm and gfs2 in cluster-3.1.0, so there is currently no way to use >> pacemaker on f13 with dlm/gfs2/clvm but without cman. >> >> So, would you please bring some light on details of integration with cman? >> >> Especially I need to understand how pacemaker integrates with cman's >> fencing/dlm subsystem: >> *) Do I need to configure fencing in both cman and pacemaker? > > No. Just in Pacemaker. > fenced spins waiting for Pacemaker to make an API call that tells it > that fencing completed, at which point the dlm can continue. > > David (author of fenced and the dlm) and I discussed this at length > and we are in agreement that is the right (and safe) intermediate > step.
Aha, fencing works this way too, thanks. I thought that cman should be a fencing master. Although I caught one problem when node were fenced (actually started after manual forced poweroff) but fenced daemon still thought that it is in a 'fencing' state. pacemeker did its job (tengine_stonith_notify: Notifing CMAN that 'v02-b' is now fenced) but cman (actually master fenced instance) never got it. And this seems to be related to bugreport I referred to - it seems like all nodes left fenced:default group just before that. Oh, all that dlm-related things are so unstable... :( fenced tried to fence node itself, but didn't succeed just because it doesn't have any fence agents configured. ... >> And one more question/proposal about CMAN/DLM/GFS2: >> now it is possible to use DLM/GFS2 on nodes without pacemaker installed. >> I mean, if I configure additional node in cman but have no pacemaker >> started on that node, then I'm still able to mount GFS2 on that node. >> One minor problem is that rest of pacemaker cluster waits for that node >> to start pacemaker too. > > Did you try this? Only cman membership yet. Trying to make it once more, but without success yet... Will try more a little bit later, after solving that problem with fencing domain. >From what I saw, pacemaker (correctly) shows that node as 'pending'. And allocates clone instances for it. I'd want to get rid of that instances. > Its no different to running just corosync on a node. Yes, but cman plugins are now mandatory for dlm/gfs. BTW is supposed that pacemaker should not care about dlm_controld and friends anymore? Or it will receive enough information from cman about whole DLM subsystem? > >> So all clone resources are extended with one >> more instance which "will never be started". On the other hand I see in >> pacemaker sources, that there are two types of nodes: member and ping, >> and all resource processing is done only for nodes which are members. >> Would it be too hard to add one more node type, f.e. "arbiter" (it >> participates in cman cluster so it influences quorum/fencing), which is >> only valid for CMAN clusters and is not supposed to run any resources? >> Then clones will not try to extend on that arbiter nodes, fewer >> resources, less computations, cleaner 'crm status' output. >> >> Could you please comment on this? > > Before trying thought experiments, its best to get the starting point > correct :-) Ahm, what exactly do you mean? :) > >> >> Thanks, >> Vladislav >> >> _______________________________________________ >> Pacemaker mailing list: Pacemaker@oss.clusterlabs.org >> http://oss.clusterlabs.org/mailman/listinfo/pacemaker >> >> Project Home: http://www.clusterlabs.org >> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf >> Bugs: >> http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker >> > > _______________________________________________ > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: > http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://developerbugs.linux-foundation.org/enter_bug.cgi?product=Pacemaker
