As DBAs, it is likely that we will eventually preside over a server replacement. Whether this is to avoid failed hardware or due to system upgrades, our job is to move PostgreSQL from one system to the next.
It is not simple to perform a server migration while simultaneously maintaining maximum availability. One of the easiest methods is limited to users of shared storage such as a SAN. Such storage can be reassigned to another server easily. Without a SAN or other means of shared storage, we need to utilize another method.
Luckily, PostgreSQL added streaming database replication in Version 9.1. With this, we can make a copy on the new server and switch to it when we're ready.