VMWare, esxtop Host group

A group contains multiple worlds.

You've not provided any screenshot?

A powered-on VM has a corresponding group, which contains multiple worlds.

There are other groups besides VM groups.

* The “idle” group is the container for the idle worlds, each of which corresponds to one PCPU.

* The “system” group contains the VMKernel system worlds.

* The “helper” group contains the helper worlds that assist VMKernel operations.

* In classic ESX, the “console” group is for the console OS, which runs ESX management processes.

In ESXi, these ESX management processes are running as user worlds directly on VMKernel.

So, on an ESXi box you can see much more groups than on a classic ESX, but not the “console” group.

So is the host utilization basical 100 - %idle for the aggregate of 'system' and 'helper' ?

host utilization - which esxtop metric are you referring to here?

* “%IDLE”

The percentage of time the VCPU world is in idle loop. Note that %IDLE is included in %WAIT. Also note that %IDLE only makes sense to VCPU world. The other worlds do not have idle loops, so, %IDLE is zero for them.

Simons article, may be better reading and understanding of esxtop

http://simongreaves.co.uk/blog/esxtop-guide

I've found the document I've been looking for, which breaks the ESXi server into block components, which I think you will find interesting, and help you visualise these components.



Source
http://www.vmware.com/files/pdf/vmware_esxi_architecture_wp.pdf