Once I had a place to put my data, I began filling the NAS. The TS-439 automatically creates a number of shares including Qmultimedia, which is used by the media server as the default content directory. I moved my Video library into this share so that it would be accessible to the built in Twonky media server. I also moved my Mac Time Machine network backup from the Mac Mini to the NAS.
About this time, the fourth drive arrived and I could finally expand the RAID to 2.7 TiB. I followed the instructions as presented on the QNAP website and started the RAID expansion. While the RAID is being expanded, it is still accessible at the previous smaller size and the data is protected. Once the expansion is complete, the file system is resized and the new space is available for use. The expansion process, going from a 3 drive 1.8 TiB RAID-5 to a 4 drive 2.7 TiB RAID-5, took approximately 2 days and 9 hours. Once the expansion was complete, the NAS showed the correct size and I had a 2.7 TiB RAID-5.
At this point, the TS-439 had checked out and was fully configured; now it was time to really put it through its paces.