vCenter provides even more counters at ESXi level: 32 counters for RAM plus 11 for VMkernel RAM. VMkernel has around 50 processes that are tracked. As a result, a cluster of 8 ESXi can have about 800 counters just for ESXi RAM! The counters are shown in the next screenshot. Most of them are not shown as a percentage, making it difficult to compare across ESXi with different memory sizes.
ESXi: RAM counters
As for the VMkernel processes, they are not shown under the Memory group, but under the System group. In most cases, you do not need to track the CPU or RAM consumed by the kernel processes. If you are curious, you can see the individual process (for example, vMotion, storage vMotion, hostd, vpxa, and dcui) consumption of CPU or RAM, as shown in the following chart. While Virtual SAN is a kernel module, the vSphere 5.5 Update 2 performance counter does not track it. You will need a separate tool for now to track Virtual SAN.
