HP Integrity rx4640 Server - Manual (Page 40)

Replacing, moving, or adding hard drives 40
drive in the array. Each logical drive keeps the same fault-tolerance method in the enlarged array that it
had in the smaller array.
When the expansion process has finished, you can use the liberated storage capacity on the enlarged
array to create new logical drives. Alternatively, you can use ACU to enlarge (extend) one of the original
logical drives.