I'm not sure if it's new enough to work with GPT, but if it is it could be an option. I also just recalled I have Acronis Disk Director 12 which I think is a bootable disk. It keeps slipping my mind, I'll need to give it a go. I have used the diskutil terminal command before, last time being when Fusion debuted I tried making a hybrid RAID 0 + Fusion startup drive (it worked!).

command below with 4 above: diskutil partitionDisk /dev/disk3 1 GPT HFS+. This includes hard disks, solid state disks, optical discs, disk images, APFS volumes, CoreStorage volumes, and AppleRAID sets. I go back to disk utility and Macintosh HD is gone, it has been replaced with. It provides information about, and allows the administration of, partitioning schemes, layouts, and formats of disks.

Disk Utility was far less horrible back then so there was less need for it anyway. diskutil manipulates the structure of local disks. diskutil partitionDisk /dev/disk4 1 GPT 'HFS+' 'MemTest86' 100 output: This gives me what I would expect, the first partition is an EFI partition of size 209.7MB and the remaining 3.6GB, on a 4GB drive, being allocated to the second partition, /dev/disk3s2, MemTest86. I ran into some kind of an issue with it after a year that had me ditch it. I bought Diskwarror years ago, back in the late Powermac era. Second was attempting to reformat a FAT12 (not a typo, was emulating a floppy) formatted flash drive, Disk Utility refused to touch it in any way, partition option was greyed out, everything else just spat out an error stating that it 'failed'.īoth were solved in about 10 seconds using diskpart from the Windows command line - after spending 7 minutes digging the Windows system out of it's cubby, plugging it in, and booting it up.

Be sure you use your target/disk by name instead of just /disk6 as exampled above. I needed to change it from MBR with 2 partitions to a single with GPT. Try using the command line/terminal: diskutil partitionDisk /dev/disk6 MBRFormat 'MS-DOS FAT32' 'partition name' 100. Disk Utility refused to let me do anything to the partition table on an externally attached hard drive - partition option was just greyed out so you could do literally nothing.

Diskutil partitiondisk