Abstract: A method for selectively controlling reutilization of space in a virtual tape system (VTS) having a buffer and a multiple volume tape cartridge includes transferring data volume files to the VTS. The buffer transfers the data making up these files as virtual tape volumes (VTVs) to different locations of the cartridge for storage. A file is selectively designated for the VTS to delete from storage after a date included with the file has elapsed by deleting the VTVs corresponding to the file from the cartridge to reuse space of the cartridge. The method includes detecting if a file transferred as VTVs to the cartridge has been designated for deletion. The VTS is prohibited from deleting the file after the date has elapsed if the file was not designated for deletion and is allowed to delete the file after the date has elapsed if the file was not designated for deletion.

Abstract: A method for selectively controlling reutilization of space in a virtual tape system (VTS) having a buffer and a multiple volume tape cartridge includes transferring data volume files to the VTS. The buffer transfers the data making up these files as virtual tape volumes (VTVs) to different locations of the cartridge for storage. A file is selectively designated for the VTS to delete from storage after a date included with the file has elapsed by deleting the VTVs corresponding to the file from the cartridge to reuse space of the cartridge. The method includes detecting if a file transferred as VTVs to the cartridge has been designated for deletion. The VTS is prohibited from deleting the file after the date has elapsed if the file was not designated for deletion and is allowed to delete the file after the date has elapsed if the file was not designated for deletion.

Abstract: The present invention provides a virtual automated cartridge system (ACS) and data storage device management method which incorporates a temporary data buffer arrangement between multiple user systems and conventional physical data storage devices. The temporary data buffer arrangement emulates a compatible physical data storage device when accessed by each of the user systems, but allows simultaneous allocation of different users to access to read and write data to the temporary data buffer. A control processor automatically transfers data stored in the temporary data buffer arrangement to one of the physical data storage devices when allocation to a user has ended.

Abstract: A method for selectively controlling reutilization of data space in a virtual tape system is provided which allows a user to designate whether data from a scratched virtual volume can be automatically deleted without any further action on the part of the user. This allows a user to selectively choose to create a safety net by which expired data could still be retrieved if so desired, while also minimizing the impact of such a safety net feature on the overall efficiency in space management otherwise provided by the virtual tape system.

Abstract: The present invention provides a virtual automated cartridge system (ACS) and data storage device management method which incorporates a temporary data buffer arrangement between multiple user systems and conventional physical data storage devices. The temporary data buffer arrangement emulates a compatible physical data storage device when accessed by each of the user systems, but allows simultaneous allocation of different users to access to read and write data to the temporary data buffer. A control processor automatically transfers data stored in the temporary data buffer arrangement to one of the physical data storage devices when allocation to a user has ended.

Abstract: The present invention provides a method for selectively storing duplicate copies of a virtual data volume file onto more than one multiple volume cartridge (MVC) based upon a copy indicator provided with a data volume file at the meta data file level. If access is subsequently lost to the main MVC as a result of hardware or tape failure, any copied data stored thereon is automatically recovered by accessing an MVC holding a copy of the data volume file. Thus, the amount of data which could be possibly lost is minimized without otherwise compromising the efficiency and flexibility provided by a multiple virtual volume data storage arrangement.

Abstract: A method for verifying availability of reusable data space on a selected virtual scratch tape in a virtual tape system utilizes volume label information routinely maintained in an external tape inventory management arrangement to generate labels separate from the actual volume labels stored on a corresponding tape. The volume labels are generated in a format compatible for input to an external tape management system after the selected virtual scratch tape has been mounted on a virtual tape drive. The “on-the-fly” generation of the separate volume labels based on preexisting label information allows the present invention to significantly reduce processing time and needless data transfers typically required to verify whether a scratch tape can in fact be reused, thereby increasing overall efficiency in data storage management and storage space utilization.

Abstract: The present invention provides a method for selectively reclaiming fragmented space on a multiple volume cartridge (MVC) device using a cost-benefit type analysis to determine whether making the fragmented space useable justifies moving all nonexpired data volume sets to another MVC. The present invention analyzes the allocation of space on the MVC to determine the location and size of any gaps between nonexpired data volume sets. Any gaps appearing at the end of the MVC are automatically reallocated for subsequent use. Any gaps appearing between nonexpired data volume sets are analyzed to determine whether the size and location meet predetermined criteria before moving any of the nonexpired data volume sets. In addition, the present invention allows selective movement of less than all of the nonexpired data volume sets if the size of the separating gap is larger than any nonexpired data volume sets appearing after the gap.

Abstract: The present invention provides a virtual automated cartridge system (ACS) and data storage device management method which incorporates a temporary data buffer arrangement between multiple user systems and conventional physical data storage devices. The temporary data buffer arrangement emulates a compatible physical data storage device when accessed by each of the user systems, but allows simultaneous allocation of different users to access to read and write data to the temporary data buffer. A control processor automatically transfers data stored in the temporary data buffer arrangement to one of the physical data storage devices when allocation to a user has ended.

Abstract: The present invention provides a method for selectively storing data files on a multiple volume cartridge (MVC) device which maximizes the likelihood of gaps in stored data appearing at the end of a cartridge. All incoming data files are initially stored in a virtual disk buffer, and checked to determine time of expiration. The expiration information is then used to reorder the virtual data volume files when placed on the MVC device so that the last to expire is stored first, and the first to expire is stored last.