Hi folks
We have a configuration question about HA.
situation is as follows
4 ESX Servers ( A, B, C, D ), running 3.x entreprise, 2 of them in Building A, 2 of them in building B, sites linked with 1 network 1 Gbps and 2 FC.
Servers connected to SAN storage, virtualized with Datacore products - 2 way synchronization and mirroring, with direct availability of the LUNs in Building B if storage in building A crashes (same way if Building B crashes, LUNs are available in A). So it's "online-online"
We want to implement a stretched HA cluster for these 4 nodes so that if one computer room crashes, all the VMs are automatically restarted in the other building, on the mirrored storage.
Seems a configuration perfect for a DR plan, but...
what will happen if all the links between the building fail ? no ethernet anymore, and no FC connection.
regarding Storage, we know : each site will think he is alone and will provide the LUN access to the servers, locally, in read/write mode so all the VMs are indenpendanlty available.
But how will HA work ?
We are not in an isolation case, 'cos on each site, 2 ESX are still running and they can see each other through the local network, so no way to "play" with the isolation response.
But each site will think that the other site is down, and HA will detect it, and restart all the VMs from the other site on its own ESX Servers, 'cos the LUNs are already present. this means that in this case, we would have two times the entire production running independantly in each site. (oops when the links come back ).
Is this the way it will work ?
How can we avoid this "split-brain" situation ?
Thanks for your help