How long should a device reset take?

[AC Question]

I have reset my Nexus 5 using the setting within the menu, and I have the "Erasing" Android animation still moving on screen...

...but I started this process over an hour ago and it is still going. There was a brief image of the Android robot fallen over with an exclamation mark, but then it went back to erasing.

Should it take this long? Could I do any damage by rebooting the device?

 

[B. Diddy]

Welcome to Android Central! Do you mean you did the Factory Reset from the Settings>Backup & Reset menu? Or from the Recovery Menu? Is the phone rooted?

It shouldn't take that long. I'm not sure how you'd be able to reboot the device if it's frozen on that screen. You could try forcing a power down by pressing and holding Power for 15-20 seconds, but I'm not sure if that would work on that screen.