Do I really need a UPS?

[blakeb]

I am looking at the DNS-321 NAS, and it will be used 99% of the time for strictly reading data, so I am not worried about power failure during writes. Will it damage the drives or hardware if the power lost randomly?

If so, would a more minimalistic NAS, or a router that has a USB port be a better option?

[jdabbs]

1. Possibly. Likelihood depends on frequency of power events and their intensity. Note that "power events" covers more than outages.
2. No.

A $40 UPS is more than capable of providing sufficient coverage (ancillary benefit if you can put your modem and router on it as well), or a $10-$15 surge protector as a minimum against fluctuations.

[blakeb]

Power events are not really an issue, as it will be powered through a power conditioner anyways. I am strictly worried about power outages.

[Dennis Wood]

Your first concern would be a proper shut down if power is lost, and the unit is being written to. Having a UPS that doesn't communicate with the unit will still result in a dirty shutdown, and likely reduced performance as the unit verifies it's volumes on reboot. So I'd say get the UPS to reduce momentary loss of power, and ideally use a NAS unit that has USB SmartUPS functionality. That way the unit will always power down properly and your data will stay "clean".

[claykin]

Get a NAS that can monitor a UPS via USB. This way during a power outage if the batteries run low the NAS will safely power down.