For virtual machines running on an ESX/ESXi host, instead of storing virtual machine data in a virtual disk file, you can store the data directly on a SAN LUN. This is useful if you are running applications in your virtual machines that must know the physical characteristics of the storage device. Additionally, mapping a SAN LUN allows you to use existing SAN commands to manage storage for the disk.

When you map a LUN to a VMFS volume, vCenter Server creates a file that points to the raw LUN. Encapsulating disk information in a file allows vCenter Server to lock the LUN so that only one virtual machine can write to it.


This file has a .vmdk extension, but the file contains only disk information describing the mapping to the LUN on the ESX/ESXi system. The actual data is stored on the LUN.

You cannot deploy a virtual machine from a template and store its data on a LUN. You can only store its data in a virtual disk file.


Select a target LUN.


Select whether you want to store the LUN mapping file on the same datastore as the virtual machine files, or whether you want to store them on a separate datastore.


Select a datastore.


Select a compatibility mode.


(Optional) Configure advanced options by selecting a virtual device node.