Now-a-days data is increasing rapidly, so to store these data the people need data storage technologies. In this paper, the authors have calculated estimated growth over 10 years of increasing volume of data. Also have compared data storage technologies like Direct Attached Storage (DAS), Network Attached Storage (NAS) and Storage Area Network (SAN). They have focused on emerging data storage technology such as cloud storage and included some strategy for removing unwanted data. There is inclusion of advance data storage devices such as holographic data storage and memory stick.