If you worry about data offline backup is the only "solution" hence RAID has little value (to my thinking). I'd throw all the drives in a PC (forget NAS per se) and use it as a server... your pick of OS. Or replace all of the small drives with a couple of larger ones and use a low-end single board computer like an ODROID or the new Raspberry pie (finally fast enough to use for online storage...) as a server. Create a top level directory for the data you are "worried" about and simply backup that directory and keep a copy offline. Typical media and such why bother backing up (unless you want to purchase additional drives) as it can be relatively easily duplicated.
I used to be a big NAS fan until I used them for several years and found often they only give one a sense of security. Especially when you "hang out" at their forums and see the ongoing issues. Such as deleting a volume when you think you are deleting its latest Snapshot.
Now for pure storage why not... although other alternatives often provide better solutions including the power to support various network apps.
I used to be a big NAS fan until I used them for several years and found often they only give one a sense of security. Especially when you "hang out" at their forums and see the ongoing issues. Such as deleting a volume when you think you are deleting its latest Snapshot.