Why does my 3TB Seagate HD keep formatting as a Logical Volume Group
I also have this issue... MacPro, 3TB drive (Seagate). I have to use the terminal:


diskutil list
diskutil unmount /dev/disk22
diskutil eraseDisk HFS+ "Macintosh HD" /dev/disk22
 

etc etc to utilize this drive correctly. (Sorry for all the commands. Posting them just in case it helps someone. Though anyone using those commands better know what they do first!)