First, please excuse my ignorance on this topic. Until recently I had been blissfully ignorant of this field and only recently began to suspect that I'd need to become directly involved. In any case I find myself feeling about and trying to get a survey of potential issues. This the first in what may well be many questions, let's hope I don't screw up too badly.
At work I've been told that we have three ESXi 4.x systems in a cluster. As a result of being the certified hardware tech in addition to other duties I was checking these servers warranty status and associated information. I noted that the three servers have only 2 physical NICs each. So then it dawns on me that the primary admin has been complaining about these three machines and not being able to do some specific network configuration that he has in mind.
So I start getting a little itch that something isn't right. In a past life I know we had a quartet of clustered servers that had 6 physical NICs each so that they had redundant paths to their private cluster only network, their iSCSI interface to the storage array and then redundant paths to the 'real' network.
All of which leaves me with the following questions:
- Does that logic apply to an ESXi cluster?
- Do they need a private network for health and system state communications?
- Shouldn't there be a 'shared' disk or volume for the cluster to be able to fail over? If my understanding of the configuration is correct, each member of the cluster has images for the systems they're running, which doesn't seem right. I can't imagine how ESXi would be fault tolerant if the disk array spins down on a member.
- Would a vSwitch figure in here and how? One of the complaints from the other administrator is that he's not certain that the cluster can span switches or share network space (i.e. a VM on Host A is able to reach a VM on Host B via a shared internal network).
- Given the nature of my questions, is there a recommendation for some form of deep-dive immersion to get up to speed? Training? Books? Website? Hypnotherapy? Or should I just drink the Kool-Aid?
I'm not certain that this shouldn't be configured as a community wiki as several of the questions 'feel' opinion based. Here to hoping there is a single opinion for at least some of the questions.
Thanks for the help and any amount of clue is appreciated.