The selection of storage technologies has never been greater. Today’s choices range from ultra-high capacity, low cost, low performance storage at one end to highly advanced data management functionality and very high levels of performance at the other. Future technology developments promise to further accentuate the differences between the available solutions while increasing the number of choices. Many of these options represent unique levels or tiers of the storage hierarchy. The foundations of tiered storage had their beginnings over 20 years ago when disk, automated tape libraries and advanced policy-based data management software combined to effectively migrate less active data to less expensive storage devices.