Problem : Unsupported or invalid disk type 7. Ensure that the disk has been imported.

You can run into this problem when you try to power on virtual machine on Esxi that converted from physical to virtual machine. An error message prompt and running of vm will stop. The message looks something like :

This problem occurs when you are converting physical machine to virtual one , actually the The VMs were converted and set to preserve the controller, which was IDE. The disks were also in sparse format. The VM would not boot because the controller was set to lsi sas which will not work with sparse disks. If this is changed then the VM will power up successfully.
Resolution : First up, open putty SSH session then type the following :
cd vmfs

 Note that datastore1 is sample name , just type your datastore name , if you don’t know what is it , just type “ls” after volumes you will see a folder in greeny color , it’s the datastore name.
Then type :

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Note that xxxxx is disk name of the related virtual machine , the process will convert  disk type to zerothick , if the process success try to run your machine , if its not successful the following message may appear :