best way to mirror partitions

Folks, I want to mirror my linux partitons to another drive before running checks on the original HD. There are numerous ways to "mirror" filesystem including dd, tar, cp, cpio, etc... In addition there are utilities to do the same thing. The question is, which method is best at preserving the copy as closely as the original? thanks, Babu __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com