Hi all, I am replying to this thread to share the experience with such setup. Proposed solution with corosync, pacemaker, DLM, cLVM, GFS2 is too complicated and in some cases fragile. For example, at the start, we hit an ugly bug in libqb, which wasn’t fixed until the Centos 7.3 release. It causes crashing the whole cluster every month, worse availability that in non-ha setup. Administration of such thing is complicated, requires experienced people and time. We are going throw away the whole structure and replace it with a simple one. We are staying with FC SAN storage, but we leverage storage API and write custom OpenNebula storage driver. There is no clustering, no complex solution, but simple, easy to understand, and also better performing. I like to tell others that simple is better, and you should think about that. I want to share our storage driver, which uses HPE 3PAR FC SAN [Contribution] HPE 3PAR Storage driver.