Hi Andrew, that means (when I understand it right), that with this setting you get two different semantics about what the cluster knows about itself.
With setting of a+c as recommended by you the 2-node-cluster does not get quorum in case only one node survives, but ignores that info. With the setting of b) the cluster does get quorum even when only one node is left. In this case I need not set c) as pacemaker believes having quorum (told by cman). Is this right? Best regards Andreas -----Ursprüngliche Nachricht----- Von: Andrew Beekhof [mailto:and...@beekhof.net] Gesendet: Montag, 15. April 2013 05:58 An: The Pacemaker cluster resource manager Betreff: Re: [Pacemaker] RHEL6.x dependency between 2-node-settings for cman and quorum settings in pacemaker On 12/04/2013, at 4:58 PM, Andreas Mock <andreas.m...@web.de> wrote: > Hi all, > > another question rised up while reading documentation concerning > 2-node-cluster under RHEL6.x with CMAN and pacemaker. > > a) In the quick start guide one of the things you set is > CMAN_QUORUM_TIMEOUT=0 in /etc/sysconfig/cman to get one node of the > cluster up without waiting for quorum. (Correct me if my understanding > is wrong) > > b) There is a special setting in cluster.conf <cman two_node="1" > expected_votes="1" > </cman> which allows one node to gain quorum in > a two node cluster (Please also correct me here if my understanding is > wrong) > > c) And there is a pacemaker setting > no-quorum-policy which is mostly set to 'ignore' in all startup > tutorials. > > My question: I would like to understand how these settings influence > each other and/or are dependent. a) allows "service cman start" to complete (and therefor allow "service pacemaker start" to begin) before quorum has arrived. b) is a possible alternative to a) but I've never tested it because it is superseded by c) and in fact makes c) meaningless since the cluster always has quorum. a+c is preferred for consistency with clusters of more than 2 nodes. > > As most insight as possible appreciated. ;-) > > Best regards > Andreas > > > > _______________________________________________ > 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://bugs.clusterlabs.org _______________________________________________ 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://bugs.clusterlabs.org _______________________________________________ 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://bugs.clusterlabs.org
