Cloning VM in power on state

Hi Team,

          I want to clone the VM when it is in power on state .

          1) Will it take much time when compare with cloning the powered off machine

          2) And at the same time i want snapshots also how can i get those. Because when i did cloning the machine in powered off state i didn't get any snapshots for the new VM

Thanks in advance,

Sasikumar.