How to clone a Virtual Machine with Raw Device Mapping (RDM) disks

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

When attempting to clone a virtual machine (VM) that has a Raw Device Mapping (RDM), the RDM is converted to a standard virtual disk (VMDK).

This article provides steps to reconnect the source RDM disk to the destination virtual machine.

Environment

VMware ESXi
VMware vCenter 

Resolution

The steps are as follows:

1. Log in to the vSphere Client 
2. Select Virtual Machine > Actions > Edit Settings
3. Select the RDM disk and click "Remove device."
4.Select Virtual Machine > Actions > Clone to virtual machine.
5. Select Virtual Machine > Actions > Edit Settings
6. Select Add New Device > RDM Disk and re-attach the original LUN.