Android Police, Google said current Nexus devices will not support seamless updates, and the reasoning given makes it sound like no current Android device will be able to handle the feature. Google said seamless updates require dual system partitions, and the act of creating those two partitions is apparently something that can't really be done by an end user, at least not without the potential for bricking your device.But, we are getting some info on seamless updates, and the early news is not that great. According to
Google apparently made it sound like creating the dual partitions would theoretically be possible with the help of a computer, but the likelihood of bricking the phone is too high to give users the option officially. Of course, that means we'll more than likely see some trickery from the XDA world, if you're the adventurous type.
So, seamless updates will probably never come to any current Android phones, but once devices start launching with Android N, you'll be good to go.
source: Android Police