System and method for managing storage space on a sequential storage media

An independent method for reclaiming space occupied by one or more data objects, the method comprising:

• obtaining a first catalog identifying a plurality of data objects stored on a source storage media;
• creating a unified catalog based on the first catalog;
• reading a reclamation catalog containing one or more entries that identify obsolete data objects;
• modifying the unified catalog in accordance with the reclamation catalog such that the unified catalog excludes the obsolete data objects;
• copying data objects not excluded in the unified catalog from the storage media to a destination storage media;
• and
• writing to the destination storage media a second catalog identifying the data objects written to the destination storage media.

A computer-readable medium having a plurality of data structures sequentially stored thereon, comprising:

• a first data structure in the plurality of data structures including a plurality of data objects;
• and
• a second data structure in the plurality of data structures, including:
• a first data field identifying the first data structure, and
• a second data field identifying an obsolete data object in the first data structure;
• such that when data in the second data structure is processed, the identity of the first data structure is determinable from the first data field of the second data structure, and the obsolete data object is determinable from the second data field of the second data structure.

A storage management system, comprising:

• a storage media;
• a storage process configured to access information stored on the storage media;
• and
• a reclamation process configured to reclaim space occupied by one or more obsolete data objects,
• wherein the storage process writes a reclamation catalog to the storage media identifying at least one of the one or more obsolete data objects.

A computer-readable medium having a data structure stored thereon, comprising:

• a plurality of data objects within the data structure, at least one of the data objects representing information contained within a data file, and another of the data objects representing a catalog of the data objects within the plurality of data objects;
• and
• a header field within the data structure, wherein the header field includes a generation number indicating whether a reclamation process has been performed on the data structure,
• such that when data in the data structure is processed, the generation number is read to determine whether other data needs to be updated with at least one of the plurality of data objects of the data structure.

A computer-implemented method for maintaining information about a storage media, the method comprising:

• reading a generation number stored in association with the storage media, the storage media including a catalog describing contents of the storage media;
• determining whether the generation number is consistent with a version of the catalog stored separate from the storage media;
• and
• if the generation number is inconsistent with the version of the catalog stored separate from the storage media, obtaining the catalog from the storage media.

An independent method for reclaiming space occupied by one or more data objects, the method comprising:

• obtaining a first catalog identifying a plurality of data objects stored on a source storage media;
• creating a unified catalog based on the first catalog;
• reading a reclamation catalog containing one or more entries that identify obsolete data objects;
• modifying the unified catalog in accordance with the reclamation catalog such that the unified catalog excludes the obsolete data objects;
• copying data objects not excluded in the unified catalog from the storage media to a destination storage media;
• writing to the destination storage media a second catalog identifying the data objects written to the destination storage media;
• writing a mapping catalog to the destination storage media that correlates the data objects on the destination storage media with a corresponding data object on the source storage media;
• and
• writing a generation number to the destination storage media.

A storage management system, comprising:

• a storage media;
• a storage process configured to access information stored on the storage media and to write a generation number to the other storage media;
• and
• a reclamation process configured to reclaim space occupied by one or more obsolete data objects, to read information from the storage media and write the information to another storage media while excluding from the other storage media the obsolete data objects identified in the reclamation catalog, and to write a new catalog to the other storage media that defines a relationship between the information stored on the storage media and the information stored on the other storage media
• wherein the storage process writes a reclamation catalog to the storage media identifying at least one of the one or more obsolete data objects, and
• wherein an application associated with the storage management system is configured to update an application specific catalog based on information in the new catalog if the generation number of the other storage media is inconsistent with the application specific catalog.