The Thecus N4200 isn't like some NAS devices. It doesn't boast fancy features most users don't want and will never bother even trying out as its major selling point. Rather, this "Zero-Crash with Dual Power NAS" has a different bent: stability. And that's a pretty clever pitch, actually.
Having recently had my NAS fail on me, I'm well aware of the necessity for stability and reliability in such devices. While it is all well and good espousing the benefits of a network-accessible repository for all of your files, but having faith that it won't up and kick the bucket, leaving said files worryingly inaccessible, is of prime importance. I, for one, therefore am at least a little interested in a NAS that promises not to fail on me.
There are two main aspects to the inherent stability of the Thecus N4200: 'Dual DOM' and 'Dual Power.' The use of two DOMs means that should one of them suffer from some manner of error, the NAS will still function with critical system software stored on the secondary DOM - this can then can be coped back across to the primary unit. A quite neat sub-feature of this is the option to enable DOM 'Auto Repair' which backs up configuration settings so they won't be lost in the event of a failure.
The dual power system comes in the form of a li-ion battery module that can be installed in the rear of the N4200, providing a backup to the mains connector in the event of a power failure. Obviously battery power won't last indefinitely, but if it’s a choice between losing data or getting an email to say there's been a mains power failure, in the event that a non-the-wiser cleaner borrows your NAS' socket for a vacuum cleaner, I know which I'd pick.
If you have access to a more serious UPS, the N4200 can communicate with that via either USB or an RS232 port. The latter inclusion is a step up from the more consumer-orientated NAS devices we've looked at recently, and gives this system a better chance of inclusion in a business setup than some of those units.