You can create a virtual disk, use an existing virtual disk, or create Raw Device Mappings (RDMs), which give your virtual disk direct access to SAN. A virtual disk comprises one or more files on the file system that appear as a single hard disk to the guest operating system. These disks are portable among hosts.

You use the Create Virtual Machine wizard to add virtual disks during virtual machine creation. To add disks later, select the Do Not Create Disk option and use the Add Hardware wizard in the Virtual Machine Properties dialog box.


You cannot reassign virtual disks to a different controller type.

You can select from the following options:

When you create a virtual disk, you can specify disk properties such as size, format, clustering features, and more.

You can use an existing disk that is configured with an operating system or other virtual machine data. This choice allows you to freely move the virtual hard drive from virtual machine to virtual machine.

You can store virtual machine data directly on a SAN LUN instead of storing it in a virtual disk file. This ability is useful if you are running applications in your virtual machines that must detect the physical characteristics of the storage device. Mapping a SAN LUN allows you to use existing SAN commands to manage storage for the disk.