How many VMs can be created in a high availability cluster?

The article contains an example of how to calculate the maximum number of VMs that can work in a high availability cluster.

For example, a cluster consists of four nodes. Each node has 256 GB of RAM. All VMs are created with 2 GB RAM.

The maximum number of RAM allocated to VMs in a high availability cluster is calculated using the formula: R = M*Q, where:

• M — the size of cluster node RAM,
• Q — the minimum number of nodes required to provide high availability. Q = N/2 +1, where N is the total number of cluster nodes. The Q value must be rounded down to a whole number.

Thus, R = 256 GB * (4/2 + 1) = 768 GB. Without taking into account overselling, you can create 768/2 = 384 VMs in the cluster.