Hi, I don't think this is a issue but I just want to ask if this is a expected behaviour. When I start the computer in recovery mode (cmd+r) and I'm trying to format the drive I'm getting a error after a little time "Couldn't unmount disk" but if I'm trying to format the Macintosh HD partion it do work without any error. If I boot up trough a USB drive (alt(option)) I can format the "main" drive without any issues, I can also format it if I'm booting up from internet recovery (cmd+alt(option)+r) Is this issue because when I'm starting in recovery mode it starts up from the recovery partion and because of that I can't format the "main" disk but only the "Macintosh HD" partion. But when I'm booting from USB drive and internet recovery I can format the "main" disk because then the disk are not busy because of the Recovery partion. Is this correct?