Hello everybody, I tried the usual factory reset procedure with my new Mac but have a serious problem with it. I used cmd + R, entered disk utility, and tried erasing Macintosh HD but had the "Unable to delete the core storage logical volume" error so I can not reinstall the OS. In disk utility I see 2 Macintosh HD one inside the other. They have unusual formats like logical volume group. How can I factory reset a new iMac with fusion drive?