Abstract: An apparatus, system, and method is provided for flushing data from a cache to secondary storage. The apparatus, system, and method identifies predefined high priority cache structures and predefined low priority cache structures. The apparatus, system, and method selectively flushes low priority cache structures according to a first scheme when the cache is under a demand load and according to a second scheme when the cache is under substantially no demand load. The first scheme is defined to flush low priority cache structures as efficiently as possible and the second scheme is defined to flush low priority cache structures in a less efficient manner.

Abstract: A system, apparatus, and method to recover a logical volume on a physical volume, or data storage cartridge, within a dual copy data storage system, such as a virtual tape server (VTS) system. Such recovery follows a disaster situation involving a primary copy of the requested logical volume. The system, apparatus, and method include modules and steps as required to recover a logical volume, or data file or block, through manipulation and swapping of record files, or stubs, that point to primary and secondary copies of a logical volume. Such primary and secondary logical volumes are stored on distinct physical volumes in order to provide quality storage media management and reduce the likelihood of loss of data.

Abstract: Disclosed is a system, method, and program for accessing a data set, e.g., volume, file, from one of two storage devices. Each storage device includes a copy of the data set. A flag is maintained for each storage device indicating whether a previous access attempt of the data set from the storage device failed. The storage device having the flag indicating that no previous access attempt failed is selected if the flag for the other storage device indicates that one previous access attempt of the data set from the storage device failed. The data set is accessed from the selected storage device.

Abstract: A system, apparatus, and method to recover a logical volume on a read-only physical volume, or data storage cartridge, within a dual copy data storage system, such as a virtual tape server (VTS) system. The recovery follows a disaster situation involving the primary physical volume and the requested logical volume. The system, apparatus, and method include modules and steps as required to recover a logical volume through recalling a selective dual copy of the logical volume stored on a secondary physical volume. The primary and secondary logical volumes are stored on distinct physical volumes in order to provide quality storage media management and reduce the likelihood of loss of data. The recovery and recall procedures are implemented in a manner that is substantially transparent and asynchronous to a host or client. Additionally, the recovery and recall require no additional input from the host in order to carry out the recovery of the logical volume.

Abstract: Provided are a method, system and article of manufacture for return processing in storage pools. A plurality of physical volumes are allocated to a first storage pool. A determination is made whether the first storage pool has more than a threshold number of empty physical volumes. If the first storage pool has more than the threshold number of empty physical volumes, then at least one empty physical volume is returned to a second storage pool.

Abstract: Disclosed is a system, method, and program for transferring data. Whether data is being transferred to physical volumes in peak mode is identified. If the data is being transferred in peak mode, whether a large chain of data is available for transfer to physical volumes is determined. If the large chain of data is not available, whether a small chain of data is available for transfer to physical volumes is determined. If the small chain of data is available, the small chain of data is transferred to physical volumes. Additionally, if one or more files that have ages greater than a steady state age threshold are available, the one or more files are transferred to the one or more physical volumes. If one or more files that have ages greater than a peak age threshold are available, the one or more files are transferred to the one or more physical volumes.

Abstract: Provided are a method, system, and article of manufacture for pooling of storage. Volume attributes are assigned to a plurality of physical volumes. Pool attributes are assigned to a plurality of storage pools, wherein the pool attributes include policies for borrowing and returning the plurality of physical volumes to and from the plurality of storage pools. One of the plurality of physical volumes is allocated to one of the plurality of storage pools based on the volume attributes of the one of the plurality of physical volumes and the pool attributes of the one of the plurality of storage pools.

Abstract: Provided are a method, system, and article of manufacture for borrow processing in storage pools. A plurality of physical volumes are allocated to a first storage pool. A determination is made whether the first storage pool has less than a threshold number of empty physical volumes. If the first storage pool has less than the threshold number of empty physical volumes, then at least one empty physical volume is borrowed to the first storage pool from a second storage pool.

Abstract: Provided are a method, system, and program for managing storage units. Storage pool information indicates an assignment of a plurality of storage units to a plurality of storage pools, wherein each pool is assigned zero or more storage units, and wherein data associated with one storage pool is stored in at least one storage unit assigned to the storage pool. User selection is received to move at least one storage unit to a target storage pool. A determination is made of at least one storage unit assigned to a source storage pool to move to the target storage pool. The storage pool information is updated to indicate the determined at least one selected storage unit as assigned to the target storage pool.

Abstract: Provided are a method, system, and an article of manufacture for optimizing storage utilization. Logical volumes are stored in a cache, wherein the cache is coupled to a plurality of physical devices. An optimum number of physical devices selected from the plurality of physical devices is determined. The logical volumes are transferred from the cache to the optimum number of physical devices.

Abstract: A method and system for efficiently importing/exporting a removable storage volume having a number of data files from a first virtual storage system to a second virtual storage system. The method includes writing a table of contents to the end of the removable storage volume in the first virtual storage system. The table of contents uniquely identifies the data files residing in the removable storage volume. Next, the removable storage volume is transferred to the second virtual storage system. Upon receipt of the removable storage volume, the second virtual storage system updates a database in the second virtual storage system utilizing the information contained in the table of contents without having to read each of the data files in the removable storage volume. In a related embodiment, for each of the data file in the removable storage volume, the table of contents includes a filename, starting record on the removable storage volume and number of records in the data file.

Abstract: Provided is a method, system, and an article of manufacture for maintaining data accessible by a host in two storage devices, wherein the data is comprised of a plurality of data sets. A determination is made of a percentage of uncopied data at the first storage device, wherein uncopied data comprises data sets to be copied from the first storage device to the second storage device. If the calculated percentage is greater than a threshold amount, a rate at which uncopied data sets are transferred from the first storage device to the second storage device is increased.

Abstract: Disclosed is a system, method, and an article of manufacture for preferentially keeping an uncopied data set in one of two storage devices in a peer-to-peer environment when data needs to be removed from the storage devices. Each time a data set is modified or newly created, flags are used to denote whether the data set needs to be copied from one storage device to the other. The preferred embodiments modify the timestamp for each uncopied data set by adding a period of time, and thus give preference to the uncopied data set when the data from the storage device is removed based on the least recently used as denoted by timestamp of each data set. Once the data set is copied, the timestamp is set back to normal by subtracting the same period of time added on when the data set was flagged as needing to be copied.

Abstract: A system, apparatus, and method to recover a logical volume on a physical volume, or data storage cartridge, within a dual copy data storage system, such as a virtual tape server (VTS) system. Such recovery follows a disaster situation involving a primary copy of the requested logical volume. The system, apparatus, and method include modules and steps as required to recover a logical volume, or data file or block, through manipulation and swapping of record files, or stubs, that point to primary and secondary copies of a logical volume. Such primary and secondary logical volumes are stored on distinct physical volumes in order to provide quality storage media management and reduce the likelihood of loss of data.

Abstract: A method and system utilizing data fragments for efficiently importing/exporting a removable storage volume having a number of data files from a first virtual storage system to a second virtual storage system. The method includes writing data fragments to the end of the removable storage volume in the first virtual storage system. In an advantageous embodiment, the data fragments are written to the end of the removable storage volume when the removable storage volume is closed. The data fragments contain information, such as data file headers, that uniquely identifies the data files residing in the removable storage volume. Next, the removable storage volume is transferred to the second virtual storage system. Upon receipt of the removable storage volume, the second virtual storage system updates a tape volume cache in the second virtual storage system utilizing the information contained in the data fragments without having to read each of the data files.

Abstract: Provided are a method, system and article of manufacture for return processing in storage pools. A plurality of physical volumes are allocated to a first storage pool. A determination is made whether the first storage pool has more than a threshold number of empty physical volumes. If the first storage pool has more than the threshold number of empty physical volumes, then at least one empty physical volume is returned to a second storage pool.

Abstract: Provided are a method, system, and article of manufacture for borrow processing in storage pools. A plurality of physical volumes are allocated to a first storage pool. A determination is made whether the first storage pool has less than a threshold number of empty physical volumes. If the first storage pool has less than the threshold number of empty physical volumes, then at least one empty physical volume is borrowed to the first storage pool from a second storage pool.

Abstract: Provided are a method, system, and program for managing data in storage units. Storage pool information indicates an assignment of a plurality of storage units to a plurality of storage pools, wherein each pool is assigned zero or more storage units, wherein data associated with one storage pool is stored in a storage unit assigned to the storage pool, wherein the storage pool information for each pool indicates a threshold and target storage pool, and wherein the target storage pool is capable of being different from the storage pool. One storage unit associated with a source storage pool is selected and a determination is made of the threshold from the storage pool information for the source storage pool.

Abstract: A virtual storage server and library manager are configured to avoid a lengthy check-in process for selected physical volumes. In one embodiment, the selected physical volumes are volumes that were in a checked-in state previous to a disaster. Other volumes are checked-in normally. The present invention leverages information within the virtual storage server to efficiently recovery from disasters that destroy state information within the library manager. The improved recovery method, apparatus, and system, reduce the downtime associated with disasters within removable media virtual storage systems.

Abstract: Provided are a method, system, and article of manufacture for pooling of storage. Volume attributes are assigned to a plurality of physical volumes. Pool attributes are assigned to a plurality of storage pools, wherein the pool attributes include policies for borrowing and returning the plurality of physical volumes to and from the plurality of storage pools. One of the plurality of physical volumes is allocated to one of the plurality of storage pools based on the volume attributes of the one of the plurality of physical volumes and the pool attributes of the one of the plurality of storage pools.