On Thu, 21 Jun 2018 07:09:43 +0200 Klaus Wenninger <[email protected]> wrote:
> On 06/21/2018 05:52 AM, Andrei Borzenkov wrote: > > 21.06.2018 00:50, Digimer пишет: > >> On 2018-06-20 05:46 PM, Jehan-Guillaume de Rorthais wrote: > >>> On Wed, 20 Jun 2018 17:24:41 -0400 > >>> Digimer <[email protected]> wrote: > >>> > >>>> Make sure quorum is disabled. Quorum doesn't work on 2-node clusters. > >>> It does with the "two_node" parameter enabled in corosync.conf...as far > >>> as I understand it anyway... > >> It doesn't, that option disables quorum in corosync. > >> > > This option does not disable quorum - this option fakes quorum so > > corosync continues to report "in quorum" even when one node is lost. it > > is quite possible that pacemaker quorum does not map one-to-one to > > corosync quorum though. > > > >> Quorum is floor(($nodes / 2) + 1). So in a 3-node, that is 3 -> 1.5 -> > >> 2.5 -> 2 votes needed for quorum. In a 2-node, that is 2 -> 1 -> 2 -> 2 > >> votes needed for quorum, meaning you can't lose a node to operate (which > >> is kinda not HA :) ). > >> > > Let me try to shed some light on this: > With Corosync 2.x.x and up Pacemaker gets quorum from Corosync so > setting two_node there directly gives you the behavior desired. > It was with Corosync 1.x.x when Pacemaker just used the messaging > from there and had it's own quorum logic built in. This was my comprehension of the manpage. https://github.com/corosync/corosync/blob/master/man/votequorum.5#L94 Thanks for the confirmation Andrei and Klaus. _______________________________________________ Users mailing list: [email protected] https://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
