What is the outcome when an administrator tries to snapshot a physical mode raw device mapping (RDM)?

When an administrator attempts to snapshot a physical mode raw device mapping (RDM), the outcome is that the administrator will be unable to snapshot the RDM. This behavior occurs because physical mode RDMs are designed to provide direct access to the physical storage, allowing virtual machines to bypass the hypervisor layer. Since snapshots rely on the ability to create a point-in-time copy of the virtual machine's disk state and physical mode RDMs do not support this mechanism, the snapshotting feature cannot be utilized.

Physical mode RDMs are primarily used in scenarios where direct access to the underlying hardware is necessary, such as for certain types of database applications or when using advanced storage features. In these cases, the inability to create snapshots can impact backup strategies and recovery options, requiring administrators to consider alternative methods for data protection.

This limitation is specific to physical mode RDMs, while other types, like virtual mode RDMs, do allow snapshotting. This distinction is critical for administrators to understand when planning their storage architecture and backup strategies in a VMware environment.