vSphere High Performance Cookbook

Analyzing host and VM memory

Often you need to monitor virtual machine and host memory usage; the good part about this is that VMware vSphere Client exposes two memory statistics in the Summary tab of a virtual machine. These are consumed host memory and active guest memory.

Consumed host memory is the amount of host physical memory that is allocated to the virtual machine. Please note that this value includes the virtualization overhead also.

Also note that many VMs have oversized vRAM, and the guest operating system is likely to opportunistically fill up its vRAM with unnecessary things (for example, caching everything read from disk, no matter how unlikely it will be requested again). Consumed memory only means that the VM used this memory at ...