Ask Different is a question and answer site for power users of Apple hardware and software. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have Lion and Snow Leopard installed on my machine, and I switch between them all the time (I develop for compatibility on both platforms). Going into System Preferences and selecting the startup disk every time is quite a pain, it would be great if I could automate this process with a script that I can launch from my dock.

share|improve this question
Note that although it wouldn't fit your question title of "automate" you can hold the option key immediately after the boot chime to see all the accessible bootable mediums and choose the OS you want. – Arc676 Nov 20 '15 at 8:58
up vote 1 down vote accepted

sudo bless -mount /Volumes/"startup disk name" -setBoot

Press Enter.


This should work.

share|improve this answer
Saved as a bash script this fits my needs perfectly. – fredley Oct 28 '11 at 16:39

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.