[Klug-general] hard drive image

[Evan Ingram]

Hi all

I want to take an image/make an exact copy etc (not sure on the correct
terminology) of one hard drive onto another identical hard drive. 

Have a system set up and want to make changes but would like a copy of
the last known good configuration to revert back to if things go pear
shaped. Whats the simplest way of doing this? I've read about using dd,
sounds like it could be a bit slow(?). 

cheers
Evan