VMotion fails with the compatibility error: Currently connected device uses backing which is not accessible

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• Performing a vMotion or Storage vMotion in vCenter Server fails with below error:
  
  Unable to migrate from <source server> to <destination server>: Currently connected device'<device>'uses backing '<device>', which is not accessible.

Sample error screenshot:



Environment

• VMware vSphere ESXi
• VMware vCenter Server

Cause

This issue occurs when one of the connected devices is not accessible on the destination host.

The following devices may trigger this message when connected:

• CD-ROM Drive

• Floppy Drive

• Serial Port

• Parallel Port

Resolution

• If you are using an image file (ISO) ensure that it is accessible from all ESXi Servers. Store the files on a datastore that is shared between all ESXi Servers that will participate in the vMotion of the virtual machine.
  
  For example:
  
  
  • As per the error screenshot mentioned in the Issue/Introduction above, the file which is not accessible is "[Datastore] linux.iso"
  • Make sure the same path ([Datastore] linux.iso) is available on the destination ESXi host.
    
    
• Disconnect the device from the virtual machine before performing the migration if the device is not available on the destination host.
  
  For example:
  If the error is for CD/DVD drive, perform below steps to disconnect the device:
  
  
  • Navigate to the VM object in either the vCenter or Host UI
  • Right click on the VM > edit settings
  • Look for CD/DVD drive row
  • Uncheck the "connected" box to disconnect
  • Click OK to save.
    
    
• Floppy disks can be removed using the ESXi Host Client but not from the vSphere Client. If the remove option appears grayed out in the Host Client, power off the virtual machine and then remove the floppy disk.