@olivier said in Xenserver and Storage:
And it's second time I heard about the "intelligent split brain" management on StarWind but didn't see any paper nor a start of explanation about how it works (nor even a simple link). Can you elaborate please? If it's the witness node, it's the classical thing, but I'm curious about the split brain protection without using a witness node.
My understanding is they can do multiple links, multiple heartbeats,
Or a discrete and Stateful witness service on a 3rd system that will completely solve the problem.
VMware vSAN prevents this on 2 node and stretched clsutering by keeping witness components with sequence numbers on the witness system. In a vote is called the one has a updated sequence number matching the winner that side wins. In the event a stretched cluster partitions and both have matching sequence numbers the "Primary" side wins.
I'd argue isolation behavior goes beyond the storage heartbeat to how isolation is handled at the VM and Hypervisor level. STNITH is kind of a barbaric way ot handle this in 2017.
Other fencing systems that exist in VMware are for HA. Pings between hosts (Default on management network, moved to vSAN network if in use) Isolation address's (can have multiple) and heartbeats through datastore heartbeats (a file that is updated) for non-vSAN datatsore's. Based on this you can configure different VM and host isolation responses (maintain power, power off, shut down etc).