Raw device mapping (RDM) is a feature of ESX that allows a virtual disk in a VM to be created on a remote iSCSI LUN rather than on a datastore local to the ESX server. Virtual machines with virtual-mode raw device mapped disks are supported with the following limitations:
| • | Physical-mode RDM disks are automatically excluded from vProtect backups. Use agent-based backup to backup this data. |
| • | Protection with full, differential, and incremental backups are supported. |
| • | The size of the full backup is equal to the entire allocated VM disk size, rather than the used size, since change tracking is not used for RDM backups. |
| • | Upon restore, any RDM disks are restored as standard virtual disks. |