scsi_id returns nothing on OEL6 running on VMware

Today while I was trying to setup UDEV for an Oracle 12cR1 RAC environment, I found scsi_id returns nothing. After googling around, the solution is as below:

1. shutdown the VM
2. right click the VM, then left click 'Edit Settings'
3. click 'Options' tab
4. click on 'General', then 'Configuration Parameters'
5. click 'Add Row'
6. add a parameter 'disk.EnableUUID' and set it to 'True', click 'OK'

boot up the server and now scsi_id -gud /dev/sdx returns values.