ESXi Summary tab and Resource Allocation tab do not show the same values for memory and CPU

Products

• VMware vCenter Server

Issue/Introduction

This article provides information on how the ESXi Summary tab displays CPU and memory totals in comparison to the Resource Allocation tab.

Symptoms:

• The Summary tab and the Resource Allocation tab in an ESXi host do not show the same value for memory and CPU.
• The Summary tab and the Resource Allocation tab show different values for memory and CPU.

Environment

• VMware vCenter Server 4.1.x
• VMware vCenter Server 5.5.x
• VMware vCenter Server 5.1.x
• VMware vCenter Server 5.0.x

Resolution

The ESXi host Summary tab displays the values for the installed CPU and memory. It is a representation of the physical CPU and memory hardware that is installed in the ESXi host and presented by the BIOS.

The ESXi or Cluster Resource Allocation tab displays three values:

• Total Capacity – Amount of resource that is guaranteed to be available to the resource pool (ESXi host).
• Reserved Capacity – Total amount of resources that have been used for the reservation requirements of all descendants of the resource pool. This includes both child resource pools and virtual machines.
• Available Capacity – Total amount or resources available for reservation of a child virtual machine.

The values in the Resource Allocation tab are the resources, with the system resource pools already subtracted.

Note: An ESXi host is treated as a resource pool.