This. You normally CANNOT just install a drive into a NAS, WITH EXISTING DATA ON IT, and expect it to work.I would buy a drive of equal size that's on the QNAP enclosure approved list, put it in the QNAP and configure the way you want, then copy the data to the new QNAP device.
I had a NAS that would let you do that. It was a linux based appliance, so if you already had an MBR/ext3-formatted drive, it'd just recognize it and go on its merry way.This. You normally CANNOT just install a drive into a NAS, WITH EXISTING DATA ON IT, and expect it to work.