An ESXi host allocates to each virtual machine a portion of the underlying hardware resources based on several factors:

  • Total available resources for the ESXi host, resource pool, or cluster to which the virtual machine belongs.
  • Number of virtual machines powered on and resource usage by those virtual machines.
  • Overhead required to manage the virtualization.
  • Constraints defined by the user.

Resource management allows you to dynamically allocate resources to virtual machines so that you can more efficiently use available capacity. You can change resource allocation in the following ways.