How to boot from External Drive?

[Yamcha]

Hi Guys,

I have a 21.5" iMac, I installed Snow Leopard on a external drive, but I am unable to boot from it.. I've tried pressing the option(alt) key, and the only drive that shows up is the Macintosh HD..

How do I boot from the external USB drive?

Hope someone can help :]

Thanks

 

[macintoshmanic]

Booting from an external drive on a Mac

Hi Guys,

I have a 21.5" iMac, I installed Snow Leopard on a external drive, but I am unable to boot from it.. I've tried pressing the option(alt) key, and the only drive that shows up is the Macintosh HD..

How do I boot from the external USB drive?

Hope someone can help :]

Thanks

In order for you to boot from an external drive, you will need a Mac formatted firewire drive. That's about it.

 

[iShater]

In order for you to boot from an external drive, you will need a Mac formatted firewire drive. That's about it.

That is not 100% correct.

New Intel macs should be able to boot from USB IIRCC.

Op, how do you know the other drive is a bootable drive? did you format it/clone it that way?

 

[Yamcha]

I installed Snow Leopard on it using the OSInstall.mpkg file and chose GUID Partition.. (/Volumes/Mac OS X Install DVD/System/Installation/Packages) Just because I can install it while I'm on Snow Leopard..