There are many requirements for VMware HA. First one of thm is to have the right VMware vSphere license, as I mentioned above. Here are other requirements:
- vSphere Essentials Plus or higher.
- Shared Storage– you’ll need some kind of shared storage. I say some kind, since you can use dedicated storage device (NAS, SAN) or also you can use other (software based) products which emulate the shared storage, like VMware VSAN, or any NAS or SAN hardware device.
- CPU compatibility between the hosts– the ideal cluster is a cluster with exactly same hardware and memory size. Small 3 host cluster allowing to run 20-30 VMs will satisfy most of SMBs. But you can use VMware EVC to adjust cluster settings for CPU compatibility.
Once you install vCenter Server, configure a network of each of your ESXi hosts, you can start creating your cluster. Each of your hosts should have redundancy assured by using at least two physical NICs for each network:
- management network
- VM network
- vMotion network
To make this article shorter, I’m skipping the network configuration now. The installation of the vCenter server on Windows Server OS is another piece which is not covered in my article as you can simply use easy install or you can deploy vCenter Server Appliance (vCSA) – read my detailed article:
The vCSA has the advantage that its all-in-one prepackaged product, part of the bundle, and so no need to install the individual components one by one.
Another requirement for creating VMware vSphere HA cluster is solid DNS architecture with forward and reverse zones created and working. If not already done, create on your DNS server the necessary records now.