Ex2 to EX4100

i have an ex2 ultra and want to get the MY CLOUD EXPERT SERIES EX4100. now i have 2 3TB drives in the ex2. if i get the ex4100, can i move the 2 3TB drive from my ex2 to the ex4100? and not have to reformat the hard drives?

Due to change in NAS enclosure environment, drives need to be erase to set up new RAID configuration in new My Cloud EX4100. You can move the drives of EX2100 in EX4100 but need to reformat. However, you can take a backup as an alternative before moving the drives in EX4100.