There are 2 certfied EXAM. about Linux in the world.
one is RHCE
the other is LPI
The RHCE EXAM. has 3 lesson will be finished in one day
and it will take u 400 US dollars(too expensive)
So, I think it is too hard (there are only two people pass the EXAM.
in TAIWAIN)
Now I study LPI ,I think it`s a better(cheaper??) choice
(sorry,my chinese keyboard is broken)