USB key behaves as a CD My USB key behaves as a CD, because I'm not able to copy a .dmg  file from my MacBook Pro 2016 with `sudo dd if=/Users/jeremiegauthier/Downloads/ubuntu-gnome-16.10-desktop-amd64.dmg of=/dev/rdisk2 or with the following method :



Could anyone be able to tell what I need to do to allow the access?
You need to precede the dd command with sudo to give you permission.

I provide this answer with some reluctance because using dd is extremely risky. You can easily overwrite your system if you use the incorrect target. If you do not already know how to use sudo on the command line, you should look for other image copying tools, with inbuilt safeguards.