What feature allows a virtual machine to revert to a previous configuration state?

The feature that allows a virtual machine to revert to a previous configuration state is snapshots. Snapshots are a crucial tool in virtual machine management as they capture the entire state of a VM, including its Disk files, memory, and device status at a specific point in time. This means that if a change is made to the VM—whether it be a software installation, configuration change, or other modifications—and those changes result in issues, the snapshot can be used to roll back the VM to its previous state.

This functionality provides a safety net for testing and troubleshooting, as administrators can experiment with changes without the risk of permanently altering the VM's configuration. If issues arise after an update or change, the VM can be restored to the safe state recorded in the snapshot, minimizing downtime and allowing for easier recovery from errors.

On the other hand, features like Storage I/O Control focus on the management of I/O operations within a datastore, Bus Sharing relates to how virtual devices share a bus in the VM architecture, and vSphere High Availability (HA) is concerned with the availability of VMs in the event of host failures, none of which directly provide the ability to revert to a previous configuration like snapshots do.