So, how can we monitor the environment? You can use two ways—first, through an OS VM approach and second, through  a third-party tools approach. We can use two views to monitor the environment:

• Inside the guest OS tools: Task Manager, top or monitoring agents installed inside of the guest OS
• Outside the guest OS tools: vCenter Server performance charts or ESXTOP

For specific tasks, such as long-term monitoring, GUI tools are usually more powerful, but for quick identification of bottlenecks or troubleshooting, I usually prefer command-line interface (CLI). As we are covering mainly the VMware world, we will not cover how to monitor your VMs from the guest OS perspective, but we will instead focus on vSphere monitoring itself.