Modern computer systems are expected to be up continuously: even planned downtime to accomplish system reconfiguration is becoming unacceptable, so more and more changes are having to be made to ?live? systems that are running production workloads. One of those changes is data migration: moving data from one storage device to another for load balancing, system expansion, failure recovery, or a myriad of other reasons. This document gives the overview of all the process involved in Data Migration. Data Migration is a multi-step process that begins with an analysis of the legacy data and culminates in the loading and reconciliation of data into the new applications.