HIERARCHICAL STORAGE MANAGEMENT (HSM)

HSM is management created policies that determine what data is stored where and for how long before it is transferred to less expensive storage systems and media and then ultimately discarded when there is no further legal obligation to retain it.

Why use expensive disk to store all your data if it's not necessary? CAS Severn and IBM has several options around disk and tape technology to allow you to store data based on your accessibility and security needs.