An administrator is attempting an OS upgrade on a VM disk that is stored on a SAN. In the event of a failure, the administrator wants to ensure the system can return to a working state in the…

A storage-level SAN snapshot maintains a dependency on the original LUN and its metadata structures; reverting a snapshot can involve complex SAN operations (volume remapping, snapshot promotion) that add latency, and a corrupted base volume during the upgrade may affect snapshot integrity.

Storing a full file-system backup directly on the SAN takes advantage of the SAN's high I/O throughput and low latency, enabling rapid data restoration. Unlike a storage-level snapshot, a full backup is a fully independent copy that does not depend on the original volume's state or require additional SAN volume management steps - such as LUN remapping or snapshot promotion - that introduce recovery delays.

LTO tape has significantly lower sequential read throughput compared to SAN block storage, making tape-based restores substantially slower when the shortest possible recovery time is the priority.

An OS system recovery point is created and managed by the operating system itself, which may be in a broken or unbootable state after a failed upgrade, making this an unreliable recovery path.

A bit-level image on a local SSD in the VM host does not leverage the SAN's dedicated high-performance I/O fabric and requires moving large amounts of data over the host bus rather than restoring directly within the SAN infrastructure.