Fix: VMware 5.5 Importing VMDK to VM – Failed to open disk scsi0:0

I’m currently assisting on a project for Big Data which requires some VMDKs to be imported and added to existing VMs. I really don’t understand why the vendor doesn’t supply an appliance to import rather than having to build out multiple nodes from a VMDK file. The only redeeming factor among all this is that it’s only a proof of concept but my concerns have been raised about a proper production deployment. A request was made to add the VMDK supplied to 4 existing VMs which were essentially just shells waiting for disk to be assigned/attached. I copied the VMDK into the folder of one of the VMs, attached the disk to the VM and when I went to power it on I got the following error:

Failed to open disk scsi0:0: Unsupported or invalid disk type 7. Ensure the disk has been imported

The VMDK was obviously from a different version of vSphere and required the disk to be re-imported and also configured to zeroedthick. The steps followed to resolve this issue were:

1. Enable SSH access to ESXi host via the Security Profile under Configuration.
2. Open a putty SSH session to the ESXi host
3. Change directory to the folder of the VM: cd /vmfs/volumes/<datastore>/<VM_folder>
4. Run the vmkfstools utility to clone the VMDK as zeroedthick: vmkfstools -i imported_disk.vmdk -d zeroedthick new_clone.vmdk
5. Go to the datastore the VM resides on in vSphere and right-click the imported_disk.VMDK and select Delete from Disk
6. Edit the settings of the VM and connect the new_clone.VMDK
7. Power on the VM and the error is now gone
8. Close the putty session and disable SSH access to ESXi host