Flings: Apps and tools built by VMware engineers that are intended to be played with and explored. One fling, called I/O Analyzer, is a virtual appliance designed to run workloads to help baseline performance capabilities of a system. Another one, called OS Optimization Tool can enable or disable services in a Windows system image template. Some services may not be necessary, if and not running, will reduce the load on the host.
Brendan Gregg (Netflix) designed a chart called
Linux Performance Observability Tools. There is a
slide show on that page describing tools for the various modules of a Linux system. Look for the Linux Performance Tools slide show. There are others interesting slide shows as well.
Something I need to review at some point in the future: Monitorix: An Open Source, Lightweight System Monitoring Tool For Linux
RVTools is a windows .NET 2.0 application which uses the VI SDK to display information about your virtual machines and ESX hosts.
VMware esxtop: similar to Linux top, but more expressive as it shows many performance indicators for a VMware host.
Update 2017/05/12: Brendan Gregg provided an example of using perf to see if a cpu really is busy with the command:
perf stat -a -- sleep 10
and look for the "insns per cycle" line.
Update 2017/11/18: An article on how to obtain and calculate some stats: Linux’s SRE Golden Signals
