Questions about QNAP Ts-453a

We are pleased to inform you that we now offer the requested product: QNAP TS-453A

16GB is also possible, although not officially compatible. I'm not sure if it works with all 8GB sticks. In my case I have two of them installed and it works: Crucial CT102464BF160B (1x, 8GB, DDR3L-1600, SODIMM 204)

I also transferred my hard drives from my old QNAP and there were no problems at all, also had Raid 5.

Yes, that is possible - but then only Raid 0,1 and JBOD are available. Raid 5 requires at least 3 hard disks. A later extension with additional hard disks is of course possible, but a Raid 0, 1, or JBOD with 2 disks cannot simply be extended to a Raid 5 with 3 or 4 disks without reformatting the existing disks. If you want a Raid 5 in the longer term, you would either have to invest in 3 or 4 disks from the start - or later export/externalise your Nas completely, delete everything, combine the existing 2 disks with the new 1-2 disks to a Raid 5 (reformat) and play the data from the external backup back onto the new Raid 5 volume... possible, but a bit cumbersome and a certain risk if your external backup kicks the bucket during the copy process.