Currently I have (2) hard drives in a RAID-1, mirrored array. The drives are both 33.9 GB and 15K RPMS.

Is it possible to add additional hard drives to the array that do not match the size and space of the (2) that are currently installed? For example, a 72 GB 10K RPM hard drive (I have an extra laying around and I want to put it to good use).