I was using, Asus Router (RT-AC68R) which supports USB 3.0 external hard drives and can use them as network attached drive.
In other hand, I have QNAP NAS (TS-212P) which does the same functionality and connects to router through ethernet.
Basically, all the functionality that I need router with attached usb drive already does. There is no need for the QNAP NAS.
But the question is, how durable and safe to go with router + usb attached drive? By the way external hdd is – Western Digital My Passport Ultra
I need advise from professionals and experienced users.
In a practical sense, a drive can die at any time. Lifespan also depends on many more things than ‘drive type A over drive type B’. Typically within a specific model of drives, there’s a failure curve.
Backblaze has a lovely set of graphs of that in their reports
This is from their report of typical lifespans
So, the failure rate depends on age, and there’s an optimal age for the lowest failure rate.
Beyond that, you’d have different failure rates for different models in the same class – there’s a review here.
That said, there’s a few things worth considering.
Your qnap’s likely going to have 3.5 inch drives over 2.5 inch drives. They would have moderately better performance.
Many 2.5 inch drives built in USB controller and anecdotally those can be a point of failure – if not, you might just be able to swap out the controller on failure.
tldr: there’s no practical way to tell. I’ve had 2.5 inch disks that run happily for 4 or more years, 3.5 inch disks that have infant mortality, abnd everything inbetween. I’d go with poweruse and practicallity (with the USB drive) and if the NAS is gathering dust, just periodically power it up for backups