How to Boot Your Mac from Bootable Recovery Media

Scenario

You have created Bootable Recovery Media using HDM for Mac or CampTune, and want to boot your Mac from it, to perform specific tasks independently from your installed macOS.

Step 1

Make sure Bootable Recovery Media is connected to your Mac, then restart it (or turn it on if it's powered off).

Step 2

After you hear Mac startup sound, immediately hold [alt] or [option] key.

Step 3

Using directional buttons, select the Bootable Recovery Media, then press [return] to boot from it.