My Mac Pro has several internal drives where one of them is a bootable clone of OSX and my files. I decided to reformat it but it neither mounts on the Finder desktop nor allows me to erase it! Within Disk Utility the drive does appear with its correct name, but unlike my other drives (all with a single partition), only one icon is show. This is the information Disk Utility gives me about that drive: Type: Logical Volume Group Disk Status: Online Physical backing: disk1s2 If I click on the "First aid" tab I can verify or repair the disk. Either tells me that "the disk appears to be OK". The "Partition" tab doesn't allow me to do anything as it's all greyed out. The "Erase", "RAID" and "Restore" tabs for this drive are completely gone. Is my drive "bricked" or is there a way to make it work again? PS: I tried using the fcsk_hfs command as explained here but it didn't help.