Oui, j'avais essayé de transmettre une capture d'écran sans succès, c'est donc via le Code, OK :
Bloc de code:
MacBook-Pro-de-Hervieu:~ hervieuhelene$ diskutil eraseDisk jhfs+ CLE gpt disk1
Started erase on disk1
Unmounting disk
Creating the partition map
Waiting for the disks to reappear
Formatting disk1s2 as Mac OS Extended (Journaled) with name CLE
Initialized /dev/rdisk1s2 as a 29 GB case-insensitive HFS Plus volume with a 8192k journal
Mounting disk
Finished erase on disk1
MacBook-Pro-de-Hervieu:~ hervieuhelene$