IBM SONAS is also a solution because is integrating a tape tiering.
Post by George Crump (thank you)
The fastest growing data set in just about every organization today, and typically the largest, is unstructured data. This is data that’s outside of a database; essentially file data, stored on file servers or Network Attached Storage (NAS) systems. The unprecedented growth of unstructured data combined with its increased importance has created an overwhelming data protection challenge that is crippling most backup processes.
Read on here