De-duplication of data stored on tape media

A storage system to reduce storage of duplicate data on a sequential access media, comprising:

• means for receiving data at the storage system, having a processor and a memory, to be stored on the sequential access media;
• means for determining that the data is already stored at a first location on the sequential access media;
• means for storing to a second location on the sequential access media a reference that points to the data at the first location;
• means for receiving at the storage system a data request from a requestor;
• means for determining whether the data request is directed to the first location or whether the data request is directed to the second location;
• means for caching the requested data at a third location to a second non-sequential storage device logically corresponding to the first location;
• means for determining whether the requested data at the first location has been is cached at the third location;
• and
• means for providing the requested data from the third location to the requestor.

A computer-readable storage medium containing executable program instructions for execution by a processor, the computer readable medium comprising:

• program instructions that receive data at a storage system to be stored on a sequential access media;
• program instructions that determine that the data is already stored at a first location on the sequential access media;
• program instructions that store to a second location on the sequential access media a reference that points to the data at the first location;
• program instructions that receive at the storage system a data request from a requestor;
• program instructions that determine whether the data request is directed to the first location or whether the data request is directed to the second location;
• program instructions that cache the requested data at a third location to a second non-sequential storage device logically corresponding to the first location;
• program instructions that determine whether the requested data at the first location has been cached at the third location;
• and
• program instructions that provide the requested data from the third location to the requestor.

A system for reducing an amount of data stored on sequential access media, comprising:

• a storage system having a processor configured to execute a storage operating system, the storage operating system configured to:
• receive a backup data set from a backup application;
• determine that a data block of the backup data set is stored on the sequential access media at a first location,
• store to a second location on the sequential access media a reference that points to the data block at the first location;
• receive a data request from a requestor;
• determine whether the data request is directed to the first location or whether the data request is directed to the second location;
• cache the requested data temporarily at a third location to a second non-sequential storage device logically corresponding to the first location;
• determine whether the requested data at the first location has been cached at the third location;
• and
• provide the requested data from the third location to the requestor without rewinding the sequential access media.