The basic definition of tiered storage is that different classes or tiers of storage are used to host data of different business value. However, this is not just a matter of managing a hierarchy of discrete storage assets. The tiers are differentiated by service requirements, including:
- Performance.
- Capacity.
- Availability.
- Disaster recovery.
Discussion of storage tiers can often revolve around specific technologies – such as an enterprise Fibre Channel array being tier one storage and a midrange array being tier two. Nevertheless, tiered storage is best described by the value that it provides for the specific needs of the enterprise. Define storage tiers by service level before architecture.
