Abstract: According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling multiple hosts to the VTC. The cache is shared by the multiple hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to the hosts by the VTC. In another embodiment, a method includes receiving data from at least one host using a VTC, storing data received from all the hosts to a cache using the VTC, sending an alert to all the hosts when free space is low and entering into a warning state, sending another alert to all the hosts when free space is critically low and entering into a critical state while allowing previously mounted virtual drives to continue normally.

Abstract: According to one embodiment, a method for managing cache space in a virtual tape controller includes receiving data from at least one host using the virtual tape controller; storing data received from the at least one host to a cache using the virtual tape controller; sending a first alert to the at least one host when a cache free space size is less than a first threshold and entering into a warning state using the virtual tape controller; sending a second alert to the at least one host when the cache free space size is less than a second threshold and entering into a critical state using the virtual tape controller; and allowing previously mounted virtual drives to continue normal writing activity when in the critical state.

Abstract: A system to synchronize a database and a non-database resource includes an application to transmit a request to a service provider to perform an action. The service provider receives the request and performs the action, the action not being under commit coordination. The service provider further inserts an entry into an action-reversal table to reverse the action and makes the insertion permanent. The service provider, on behalf of the application, then deletes the entry from the action-reversal table. The application may then be configured to perform one of the following: (1) make the delete permanent by performing a COMMIT; and (2) roll back the delete by performing a ROLLBACK. At a later time, the service provider may reverse the action in the event the entry remains in the action-reversal table. Corresponding methods and articles of manufacture (i.e., computer-readable media) are also disclosed herein.

Abstract: In one embodiment, a system includes a processor, logic in the processor and/or memory configured to determine a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, and logic configured to store an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto. In another embodiment, a method includes determining a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, storing an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto.

Abstract: A method according to one embodiment includes selecting, by a processor, one of a WORM logical data object and a read-write logical data object for reuse as a new WORM logical data object, said processor maintaining data attributes bound to said selected logical data object until it is determined that said selected logical data object is available for reuse. At least one temporary data attribute is assigned to said selected logical data object while maintaining said data attributes bound to said selected logical data object The selected logical data object is mounted and a write command to beginning of logical data object is received to bind at least one data attribute to said selected logical data object to replace data attributes and data associated with said selected logical data object to reuse said selected logical data object as said new WORM logical data object.

Abstract: According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling multiple hosts to the VTC. The cache is shared by the multiple hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to the hosts by the VTC. In another embodiment, a method includes receiving data from at least one host using a VTC, storing data received from all the hosts to a cache using the VTC, sending an alert to all the hosts when free space is low and entering into a warning state, sending another alert to all the hosts when free space is critically low and entering into a critical state while allowing previously mounted virtual drives to continue normally.

Abstract: A method in one embodiment for operating a virtual server supporting at least one Write Once Read Many (WORM) logical data object and at least one read-write logical object includes initializing a logical data object from a common pool of the logical data objects, the logical data object bound with a member of a media type group, the member of the media type group comprising a WORM logical data object and a read-write logical data object; and reusing one of the logical data objects as the member of the media type group without ejection and reinsertion by mounting the logical data object with a write from beginning of logical data object to bind at least one data attribute to the member of the media type group to replace any previous attribute and data associated with the logical data object.

Abstract: According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling at least one host to the VTC. The cache is shared by all the hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to all the hosts by the VTC.

Abstract: A system according to one embodiment includes a processor; logic in the processor and/or a memory configured to determine a furthest physical position on a magnetic medium that unobscured data has been written to; and logic configured to store an indicator of the furthest physical position on at least one of the magnetic medium and a memory coupled thereto. A system according to another embodiment includes a processor; logic in the processor and/or a memory configured to receive an instruction to obscure data on a magnetic medium; logic configured to read an indicator of a furthest physical position on the magnetic medium that unobscured data has been written to; and logic configured to cause obscuring of the unobscured data on the magnetic medium, and terminating the obscuring upon reaching the physical position in the indicator.

Abstract: Provided are a computer program product, system, and method for synchronous mode replication to multiple clusters receiving a write to a volume from a host. A received write is cached in a memory. A determination is made of a replication rule indicating one of a plurality of replication modes for a first cluster and a second cluster used for replication for the write, wherein one of the replication modes comprises a synchronous mode. A determination is made that the replication rule indicates a synchronous mode for the first and the second clusters. The write is transmitted from the memory to the first cluster to store in a first non-volatile storage of the first cluster and to the second cluster to store in a second non-volatile storage in response to determining that the replication rule indicates the synchronous mode.

Abstract: A system according to one embodiment includes a processor; logic in the processor and/or a memory configured to determine a furthest physical position on a magnetic medium that unobscured data has been written to; and logic configured to store an indicator of the furthest physical position on at least one of the magnetic medium and a memory coupled thereto. A system according to another embodiment includes a processor; logic in the processor and/or a memory configured to receive an instruction to obscure data on a magnetic medium; logic configured to read an indicator of a furthest physical position on the magnetic medium that unobscured data has been written to; and logic configured to cause obscuring of the unobscured data on the magnetic medium, and terminating the obscuring upon reaching the physical position in the indicator.

Abstract: In one embodiment, a system includes a processor, logic in the processor and/or memory configured to determine a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, and logic configured to store an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto. In another embodiment, a method includes determining a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, storing an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto.

Abstract: A method in one embodiment for operating a virtual server supporting at least one Write Once Read Many (WORM) logical data object and at least one read-write logical object includes initializing a logical data object from a common pool of the logical data objects, the logical data object bound with a member of a media type group, the member of the media type group comprising a WORM logical data object and a read-write logical data object; and reusing one of the logical data objects as the member of the media type group without ejection and reinsertion by mounting the logical data object with a write from beginning of logical data object to bind at least one data attribute to the member of the media type group to replace any previous attribute and data associated with the logical data object.

Abstract: According to one embodiment, a method for managing cache space in a virtual tape controller includes receiving data from at least one host using the virtual tape controller; storing data received from the at least one host to a cache using the virtual tape controller; sending a first alert to the at least one host when a cache free space size is less than a first threshold and entering into a warning state using the virtual tape controller; sending a second alert to the at least one host when the cache free space size is less than a second threshold and entering into a critical state using the virtual tape controller; and allowing previously mounted virtual drives to continue normal writing activity when in the critical state.

Abstract: In one embodiment, a VTS system includes a tape volume cache, a storage drive for interacting with sequential access storage media; logic for receiving a mount request to access host data record(s) stored on a storage medium, the mount request including a virtual volume identifier of a logical volume and a logical block identifier of the first requested host data record therein; logic for issuing a locate command to position the sequential access storage medium to about a physical block in the logical volume having at least a portion of the requested host data record(s) therein based on the virtual volume identifier and the logical block identifier; logic for creating and supporting a partial virtual volume in the tape volume cache; and logic for copying at least the physical block to the partial virtual volume. Other systems, methods, and computer program products are also described, according to other embodiments.

Abstract: According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling at least one host to the VTC. The cache is shared by all the hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to all the hosts by the VTC. In another embodiment, a method includes receiving data from at least one host using a VTC, storing data received from all the hosts to a cache using the VTC, sending an alert to all the hosts when free space is low and entering into a warning state, sending another alert to all the hosts when free space is critically low and entering into a critical state while allowing previously mounted virtual drives to continue normally.

Abstract: An embodiment of the invention comprises a virtual tape system supporting at least one Write Once Read Many (WORM) logical tape and at least one read-write logical tape, comprising a processor configured to a first task and/or a second task. The first task initializes a new logical data object from a single pool of at least two logical data objects, with the new logical data object bound with a member of a media type group consisting of a WORM data object or a read-write data object. The second task reuses one of the logical data objects without manual ejection and reinsertion. The reuse may include the processor configured to cycle the logical data object through a scratch pool as a selected scratch logical data object and mount the selected scratch logical data object with a write from beginning of tape command to bind at least one data attribute to the WORM data object.

Abstract: A system to synchronize a database and a non-database resource includes an application to transmit a request to a service provider to perform an action. The service provider receives the request and performs the action, the action not being under commit coordination. The service provider further inserts an entry into an action-reversal table to reverse the action and makes the insertion permanent. The service provider, on behalf of the application, then deletes the entry from the action-reversal table. The application may then be configured to perform one of the following: (1) make the delete permanent by performing a COMMIT; and (2) roll back the delete by performing a ROLLBACK. At a later time, the service provider may reverse the action in the event the entry remains in the action-reversal table. Corresponding methods and articles of manufacture (i.e., computer-readable media) are also disclosed herein.

Abstract: Methods and apparatus are provided for dynamically compressing categories in a data storage library. In one embodiment, the method includes retrieving an identification of a first category in the data storage library, the first category being a last-compressed category. Next, an identification number of a first order of the first category is retrieved, the first order being a last compressed order. Compression is resumed of orders in the first category with an order next following the first order and continued with additional orders in the first category. If a predetermined amount of time has elapsed, the identification of the first category and the identification number of the order of the first category being compressed are stored. If, however, the predetermined amount of time has not elapsed and compression of the first category is complete, compression of a second category is begun.

Abstract: A method and apparatus for handling multi-volume datasets in a tape storage system are disclosed. In response to a write request for a multi-volume dataset, the information of the multi-volume dataset are captured by intercepting and deciphering a set of volume mount commands. Otherwise, the information of the multi-volume dataset are captured by snooping header information from a previous volume listed in a header of the multi-volume dataset. A chain of logical volume names that belongs to the multi-volume dataset is then built. Finally, the chain of logical volume names is then stored in a chain database.