On 18/09/15 03:32 AM, Ariel S wrote: > Right now we are building a(nother) cluster, that basically built from two > physical servers with VMs running resources managed by Pacemaker. Since > this is > two-node setup, and I'm constrained only to that two beefy servers, I > realize > that this would mean quorum=1 which also means no majority vote. > > The VMs have multiple cluster, eg. gateway cluster, infrastructure > cluster and > postgresql cluster. > > I'm thinking I could (probably) ask for another (weak) server which would > function as an observer, a quorum-maker. Quorum should be possible with 2 > against 1, right? I think this is possible, by setting resources priority > towards -infinity from going to that quorum-maker server which means > resources > should run on those two beefy servers. > > I probably will have to run multiple instance of corosync and pacemaker, > with > different configuration and authkey files (for each cluster in the beefy > servers) in a small-ish baremetal centos box. > > My question, is this actually feasible? Anyone have run into this > situation and > come up with such idea too? Got anything to share about this? > > > Thank you
Feasible, sure. Needed? No. Quorum is nice to have, but if you use a fence delay on a node and tell corosync to use 'wait_for_all', then you're fine. All the clusters I've built in the last 5~6 years have been 2-node only. You just need to be sure you've got the fencing/stonith sorted out well. digimer -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education? _______________________________________________ Users mailing list: Users@clusterlabs.org http://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