I have a 3 TB WD MyBook Live network drive. I would now like to format the WD disk. In Finder, iMac can see the WD network drive. However, when I tried to format the WD using the Disk Utility app, the app doesn’t even see the WD drive. How can I access the WD network drive in order to reformat it?
You can’t format NAS disks from a client computer. You have to do it from the NAS.
So in the MBL’s case you connect to the Web Dashboard and do a FACTORY RESTORE.