Do I need to format my new ext. drive before using SD?

[djbrickhouse]

Hi,

I just got a new external drive with USB 2.0 that I want to use to make a bootable clone of my current HDD then swp the two drives to have the bigger drive reside in my machine.

I see I can use SD to do this.

Do I need to use disk utility to first format the USB external drive as GUID or can SD do this for me? Or do I format first, then use SD?

I understand there may be issues with a USB drive being formatted via Disk Utility, but I read I can use GUID and partition as 1 partition to overcome the issue....

thanks!