Which vSphere feature allows an administrator to create an exact replica of a virtual machine as a safeguard prior to configuration changes?

The feature that allows an administrator to create an exact replica of a virtual machine as a safeguard prior to configuration changes is snapshots.

Snapshots capture the state, data, and hardware configuration of a virtual machine at a specific point in time. This means that if something goes wrong during the configuration changes, the administrator can revert the virtual machine back to the point just before the changes were made, preserving the original state and data.

While cloning creates a completely independent copy of a virtual machine, snapshots are specifically designed for safeguarding changes, allowing for quick rollbacks, which is particularly useful during testing or system updates. This aspect is crucial when trying to ensure that configurations can be safely modified without the risk of permanent disruption to the virtual machine’s functionality.

Other options like vSphere Fault Tolerance and vCalibration serve different purposes. For example, Fault Tolerance provides continuous availability for virtual machines, while vMotion is used for live migration of virtual machines between hosts with zero downtime but does not involve the creation of snapshots or replicas for safety. Cloning, while similar, produces a separate instance of the virtual machine rather than a point-in-time recovery option, which is not the primary focus when making immediate preparation prior to changes.