I purchased a Pro key last week, so it was time to expand the HDD array. I did so with three SATA II 750's, a Seagate replacement for a DOA and two sale-priced Western Digitals. After upgrading the config file on the flash drive with the Pro key and booting to make sure that it took, I shut down the UnRaid box and installed the three new drives. Mobo is the AsusP5B-E. Upon rebooting, the devices page allowed me to add all three to appropriate drive assignments, disk 3, 4, and 5. I returned to the main page and attempted to start the array. Of course, it told me that I had three new drives. I acknowledged this with the appropriate checked box to have the new drives cleared and formatted to start. After several hours, all three had cleared. but there was no option to format as there had been when I started with my original three drives in Basic. After trying to start the array by clearing the three new drives at the same time but never receiving a format option two more times, I gave up on trying to do all three HDDs at once. I tried one drive by assigning it on the devices page, being told that I had a new drive on the main page, acknowledging with the appropriate check box, clearing, and then, because finally I received the format option, formatting. I did the same for each of the other HDDs. All is now well with the whole system. So, now, finally, my question: was that a fluke or typical? It would be nice to know if this is typical as I build out the system. If it is typical behavior, then I will just assign the next drives one at a time.

Interesting - I tried to reproduce this, but after Clear has completed the new drives always show up 'Unformatted'.  Next time this ever happens, please try to capture the system log.

Thank-you for your response. It was probably user error of some sort. However, if I can justify the purchase of three new HDDs again, I will attempt to duplicate what seems to have been an anomaly. If it ever happens again, I will capture the sys log and sent them in. Still, I love this product.