ok pour la partition GUID, c'est fait:
Bloc de code:
diskutil eraseDisk jhfs+ Clone gpt disk3
Started erase on disk3
Unmounting disk
Error: -69877: Couldn't open device
macbook-pro-de-yann:~ yannchabannes$ diskutil partitionDisk disk3 gpt jhfs+ Clone 100%
Started partitioning on disk3
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Formatting disk3s2 as Mac OS Extended (Journaled) with name Clone
Initialized /dev/rdisk3s2 as a 2 TB case-insensitive HFS Plus volume with a 155648k journal
Mounting disk
Finished partitioning on disk3
/dev/disk3 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *2.0 TB disk3
1: EFI EFI 209.7 MB disk3s1
2: Apple_HFS Clone 2.0 TB disk3s2