If you had a VM with a USB device attached, which was imported into ESX using some sort of conversion tool e.g. VMware Converter in the past, you may find that it refuses to boot after upgrade to vSphere 4.  Possible symptoms include:

  • An error saying something similar to “Device ‘USB’ is not supported”, asking it to be removed but
  • If you try to edit VM’s hardware, it shows a USB device but doesn’t actually let you remove it

…. making it a “Catch-22”.  The issue exists because use of USB devices is not supported within VMs running on ESX (although ESX 4 does have an “unsupported” USB controller!)

One way of getting rid of the problem is to upgrade VM hardware to version 7.  As ESX 4 allows USB controllers, you get a chance to remove the device cleanly.  However, upgrading VM hardware might not be desirable for some reason.  It’s a non-reversible process which also seems a bit extreme.

Another way is to edit the .vmx file.  To do that, follow these steps:

  1. Locate the VM’s folder in its datastore, find the .vmx file and download it to your local drive.
  2. Make a copy of the file – just in case.
  3. Open the file with a text editor, locate the line mentioning the USB device and remove it.
  4. Save the file and upload it to the same folder, overwriting the original.
  5. In “Hosts and Clusters” view, remove the server from the list by right-clicking the server name and selecting “Remove from Inventory”.
  6. Go back to the VMs folder, right-click the .vmx file and select “Add to Inventory”.

The USB device should now be gone and the VM should boot up.  The last two steps in the process are very important as they force loading of the new configuration into ESX.  Without them, the old configuration will remain in force and you’ll think that the process didn’t work.

I hit this problem on one of my upgrades and was fixed using the latter method.

Hope this helps!