eTeknix checked out the ASUSTOR AS5102T 2-Bay Enthusiast NAS
A quote from the article:
ASUSTOR has one more amazing function that I?d like to tell a bit about before we move on and take a closer look at the device itself. The MyArchive function allows you to use hard disks as removable storage archives. Plug in an archive when you need it and swap it out for another one when it isn't needed anymore, or just to cut on the power consumption. It's as easy as plug and play and works by keeping any OS related files off the drives.ASUSTOR AS5102T 2-Bay Enthusiast NAS Review @ eTeknix
There is a limited amount of drive bays reserved for this function and in the case of the AS5102T it is one. Larger models allow for two bays to be used for the MyArchieve function. The lazy person can even buy additional disk trays to eliminate the need for screwing when replacing drives this way. This is also a very cost effective way of storing a lot of data, especially when we look at the Seagate Archive HDDs. The 8TB variant costs less than a 6TB WD NAS drive as we use in our tests, and that is an offer that is hard to resist. But keep in mind that these drives are heavily optimized for reading and will have bad writing performance compared to NAS drives.