Seems like after posting the NAS entries, I got a question from a friend trying to archive his photos as well as other data, i.e. media files, documents, backups, etc. So how do you decide which NAS to buy?

For everyone and anyone who asks me, I’ll always go with a dual-drive NAS. If you decide to go with a single drive NAS, you might as well go with USB disks like Seagate FreeAgents or WD Elements. So, basically you have to calculate how much storage you need. One area to start with is to see how much space you use in one year and how much that grows. My average storage needs (photos only) are about 600Gb/year. Chances are that won’t increase much unless I upgrade my cameras. I do budget a 10% increase. I do have other needs also so by the time I added everything in, it’s a large number.

Secondly, ask yourself f the NAS is your primary backup or not. If it is, it will need to be able to store all your backups. It’s good to take into account a 3-year plan so if you need 600Gb/year, then your NAS will be or must be able to grow to accomodate at least 2TB. This actually then dictates the size of your NAS. If it’s secondary storage (like in my case) where you have backups somewhere else (Hard drives, DVDs, BDs, etc) then the requirements are different. I wanted past 3-years of media (Photos & videos) on my NAS while my main backup stores everything. This required at least a capacity of 2.2TB at least which is why I went with a 4-drive unit. Most 2-drive NAS units max out at 2TB (2x2TB disks in mirrored/RAID1 config).

Finally, the next thing you need to consider is how fast you want to get the data off the NAS. I assume you’d be connecting at least via gigabit speeds. The specifications of the NAS play a part in the speed (excluding poor network speeds) aspect so normally I look at what CPU the NAS has along with the memory.

So what are my choices/recommendations?

Budget: DLink DNS-323
Cheaply priced (RM439/USD130), it’s the lowest cost 2-drive NAS I would buy myself.

I’ve only had experience with QNAP and Synology NAS units so that’s what I’ll stick with. You can go over to Smallnetbuilder and check their NAS reviews but not all are available locally in Malaysia. Here’s a handy performance chart for QNAP and Synology NASes.

Two-bay units:
Synology : DS210j or DS209
Qnap : TS-210 or TS-219

Two-bay units (higher performance):
Synology DS210+
Qnap TS-239 Pro II

Four-bay units:
Synology : DS410j
Qnap: TS-410 or TS-419P

Four-bay units (higher performance):
Synology : DS410
Qnap: TS-439 Pro II

note: this list above is from May 2010. If you need more space, you can consider the 5 and 6 bay models.