Its just a question arised in my mind.
Suppose I have few DNS servers hosted in US and want to shift them to India or somewhere. I mean can we just clone same servers here and start them ?
Most operating systems (including their installed packages) can be cloned sometimes.
cloning is a different part.
Suppose my dns servers are responcible to resolve billions of queries then?
and when i will shift them there ip will also change ? so what is the right procedure / steps to do this.
hm, first you need to decrease the TTL to an absolute minimum, to force any caching DNS servers to refrsh their databases more frequently. Then you need to move your DNS file(s) to the new server, and inform the top level domain about the new ip-address.