I have had a pretty dreadful NAS solution for the last few years - a USB drive attached to the Asus router, accessible through a Samba share. The target user for the router is probably someone who stores some family pictures to the drive, and surfs to a few web pages now and then. I am sure it works fine for that use case. I had a 2 TB and a 500 GB drive attached, both more or less full, with Crashplan running on a server to back everything up to their data centers. It turned out the shares disappeared every now and then, which made the Crashplan backend crash (no pun intended). Moderately heavy traffic on the router also caused the router itself to crash, since it probably ran out of memory. This in turn caused the file systems on the USB drives to be damaged, leading to loss of files when the file systems were repaired.
It is pretty amazing that you can develop and sell a typical consumer router/switch/access point for less than $50, but you should not be surprised that cracks pretty fast under pressure. It is time to put together a better solution - more about that in coming posts.