Can data on PC copied to DroboFS take less room on Drobo?


I copied a whole drive of data from my PC to my DroboFS which has dual redundancy enabled.

The properties for the folder on the PC showed about 600GB of data but the properties of the Drobo folder containing all that data shows only 30GB, yet all the data appears to have been copied (apart from some file properties attaching to certain files).

Can this be correct?