VMWARE convert vmdk files.

If encounter error "A virtual machine fails to power on with the error: Unsupported and/or invalid disk type" ,

use this command

vmkfstools -i <HostedVirtualDisk> <ESXVirtualDisk>

sample :
vmkfstools -i oldvmwarefile.vmdk> <new-converted-vmdk-file.vmdk>


it will convert accodingly.

source - 
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1028943

A virtual machine fails to power on with the error: Unsupported and/or invalid disk type

Symptoms

Summary

A virtual machine fails to power on with the error: Unsupported and/or invalid disk type  

Example

Module DevicePowerOn power on failed.
Unable to create virtual SCSI device for scsi0:0, '/vmfs/volumes/datastorename/VirtualMachineHome/VirtualMachineDisk.vmdk'
Failed to open disk scsi0:0: Unsupported and/or invalid disk type 7. Did you forget to import the disk first? 

Impact

The virtual machine fails to power on.

Resolution

This issue occurs if a virtual machine that is meant for VMware Hosted products such as VMware Workstation or VMware Fusion is powered-on on a VMware ESX host.

The underlying format used to store virtual machines on VMware Hosted products differs from the format used to store virtual machines on VMware ESX hosts.

To import a virtual machine stored on a VMware Hosted product to a VMware ESX host, the virtual machine should first be converted using VMware vCenter Converter. For more information on conversion, see the VMware vCenter Converter documentation.

Alternatively, the virtual machine's virtual disk files can be imported to a format understandable by VMware ESX using the command: 

vmkfstools -i <HostedVirtualDisk> <ESXVirtualDisk>

Connect to the ESX host using an SSH session or ILO/DRAC to use this command.