I couldn't realize what is the VM memory metric that you chose from the pictures, but there are different memory metrics that can be used to monitor memory usage in ESXi:
- VM Active Memory: defined as the amount of guest memory that is currently being used by the guest operating system and its applications.
- Host Consumed Memory: defined as the amount of host memory that is allocated to the virtual machine.
So ESXi consumed memory is always higher than VM active memory.
"The hypervisor knows when to allocate host physical memory for a virtual machine because the first memory access from the virtual machine to a host physical memory will cause a page fault that can be easily captured by the hypervisor. However, it is difficult for the hypervisor to know when to free host physical memory upon virtual machine memory deallocation because the guest operating system free list is generally not publicly accessible. Hence, the hypervisor cannot easily find out the location of the free list and monitor its changes."
Please share full screenshots of your chosen memory metrics
I hope it could be helpful