What Is Virtual Machine Density (VM Density)?

In the past, VM density has been a bit of a mystery. We've all heard about it—the idea that there's some magic number of VMs you can put in one physical host and still be able to run them all without any of them suffering from lack of resources. But what is that magic number? And how many VMs does it take to get there? And does it matter what kind of cloud service you're using? The answer: yes! The answer is always yes. But now, there is an answer (even if they are just approximations), which can help you figure out how many VMs your cloud service can handle before they start to get hungry and cranky. Virtual machine density is a relatively new metric used to measure efficiency and directly affects the total cost of ownership (TCO) of a cloud computing system or service. A virtual machine (VM) density refers to the number of virtual machines in a single physical host that can typically run without being starved of any resource. VM density is generally defined as the number of VMs running on a single host. However, other factors must be considered when determining if this number is high enough for proper performance. For example, you may have too many VMs running on a single host, but they are not all doing much work simultaneously (i. e. , idle) or you may have fewer VMs running on each host, but they are all busy at once (i.e. , there's no idle capacity). In either case, it's essential to understand that VM density will vary based on your workload requirements and how much time each. VM spends in an active/idle state over time and how much time each VM spends waiting for resources such as CPU cores or memory requests (which can result in latency issues).