I recently reached the storage capacity of my 4-bay Drobo loaded with four 1TB disks and have started the process of adding larger drives to the array. What a time consuming process! After inserting the first new 2TB drive, the Drobo Dashboard software estimated 51 hours to redistribute the data. After over 24 hours of rebuilding, the software still estimates 27 hours until completion. If this trend continues the redistribution process will take over 60 hours to complete. To add insult to injury, this will create zero additional usable space; all the extra capacity is saved for expansion which requires another larger drive to be added. Assuming the second redistribution takes as long as the current one is, I'm looking at 5 days of rebuilding time for a relatively small amount of data (2.4TB). The Drobo is the first RAID-type array I have used, so I don't have much to go off, but doesn't that rebuild time seem inordinately long? Does anyone have experience redistributing data on another RAID5 device? How long did it take? I understand that Drobo uses a proprietary technology that isn't actually RAID5, but it's in the same ballpark.