How can an administrator revert to a previous state of a virtual machine after an OS update?

When an administrator needs to revert to a previous state of a virtual machine after an operating system update, utilizing snapshots is an effective and efficient method. A snapshot captures the entire state of a virtual machine at a specific point in time, including its disk files, memory, and settings. This means that if an OS update introduces issues, the administrator can easily revert back to the state recorded in the snapshot before the update was applied.

By taking a snapshot prior to making updates, the administrator effectively creates a restore point. If the update causes problems, the administrator can navigate to the snapshots menu, select the correct snapshot, and revert the virtual machine to that state. This process can save considerable time and effort compared to other methods, like restoring from backups or creating templates.

While cloning a virtual machine (whether to a template or to another virtual machine) is a viable option, it does not provide the same immediate flexibility as snapshots when addressing issues from updates. Clones can serve as backups but do not capture the state of the VM prior to the update in the same way that snapshots do. Migrations, on the other hand, are typically used to move a VM to a different host or storage and do not provide a means to revert to a previous state.