[ClusterLabs] Quorum With Two Nodes And an "observer" Questions

[Ariel S]

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