In this chapter, we talked about VMs, that is, a software computer composed by a file structure that specifies the configuration (.vmx) and the virtual disk used to store data (.vmdk) and core components, such as virtual and hardware resources, OS, and VMware Tools. A VM can be deployed using different methods (created from scratch, clone, templates, and OVF/OVA) depending on the features requested. The use of a Content Library can simplify the deployment process.

We have seen that, once installed, a VM can be added or removed from the inventory, keeping the VM data. Snapshots can be used to take a specific point in time of a VM in order to quickly revert at any time in case of need. A typical use case is the patching process; before applying a new patch, taking a VM snapshot allows you to quickly revert in case of problems. Snapshots can be created and deleted, but sometimes a consolidation is required when snapshot deletion fails.

The chapter explained how to allocate resources to VMs in an efficient way to avoid overcommitment of resources that can compromise performance and the infrastructure functionality. VMs can be hot or cold migrated to different hosts or different storage devices using the vMotion and Storage vMotion features. Keep in mind that shared storage is not a requirement for vMotion.

The next chapter will cover virtual infrastructure monitoring, essential to keep your environment under control and avoid service disruption due to a failure you are not aware of. Monitoring the infrastructure allows the optimization of the infrastructure for best performance. Although vSphere is a stable and robust platform, failures, and problems may occur at any time. The chapter will explain the correct approach to troubleshoot a problem to quickly find a fix, minimizing the service downtime.