International Business Machines Corporation

Sepaton, Inc.

Sangate Systems, Inc.

Alexander Winokur

William Frank Micka

Yoram Novick

Oded Cohn

Kenneth M Nagin

Michael Howard Hartung

Efraim Zeidner

Claus William Mikkelsen

Seweryn Mokryn

Marek Mokryn

John Norbert McCauley

John N McCauley, Jr

Nimrod Rotics

Udi N Rotics

The present invention combines IP multicasting mechanisms with SCSI protocols to achieve a more efficient data replication or data mirroring scheme. The combination of the IP multicast mechanism with the mapping of virtual unit logical number to real logical unit numbers, combined with the use of SCSI response frames, ensures the integrity of multicasted data. By use of the SCSI protocol over the TCP/IP according to the present invention, there is no further need to transfer multiple copies of the same data on the same communication link, and the routing logic may be removed from initiator and targets to IP routers.

System maps SCSI device with virtual logical unit number and multicast address for efficient data replication over TCP/IP network

A system and method is described for use in the propagation of cross-platform updates of databases in, for example, an Enterprise system. Given that these platforms may be operating using different operating systems and database software, the system and method are not application dependent. The system and method effect the cross-platform propagation of updates through the use of I/O streams. Accordingly, the system and method do not use valuable and expensive CPU cycles nor excessively load the TCP/IP communication lines to perform the desired cross-platform propagation of updates for platform databases.

System and method for cross-platform update propagation

Systems and methods of servicing requests of a first file system communicated in accordance with a first storage protocol using a storage system that is responsive to requests communicated according to a second storage protocol and that is organized in accordance with a second file system. Among other things, this allows the use of potentially more reliable and robust storage systems for holding information of the first file system and allows potentially more reliable and robust management tools to manage the information of the first file system.

Method and apparatus for implementing a reliable open file system

The disclosed device, system and methods of data management facilitate the implementation of improved mirroring, back-up, volume remapping and extent relocation, among others. The disclosed intelligent I/O stream splitter may intercept and alter an I/O stream from a communications link. In the case of mirroring, the intelligent splitter may intercept write commands and associated data from a mainframe that target a specific storage location on a specific control unit. The splitter may then transmit the intercepted I/O stream to the targeted control unit and storage location over one link and transmit on another link an altered version of the intercepted I/O stream to another control unit, which is responsible for holding a mirrored version of the data. The altered version could have the same data as that on the one link, or may include new frame headers, changes to the control information, or changes to the data itself.

Device, system, and method of intelligently splitting information in an I/O system

A device, system and methods of data management are disclosed, which facilitate the implementation of improved mirroring, back-up, volume remapping, extent relocation, prefetching, caching, data reformatting, statistic gathering, and data translation, among others. A new, intelligent I/O stream splitter is disclosed that may intercept and alter an I/O stream received by the splitter from a communications link. For example, in the case of mirroring, the intelligent splitter may intercept write commands and associated data from a mainframe that target a specific storage location on a specific control unit. The splitter may then transmit the intercepted I/O stream to the targeted control unit and storage location over one link and in parallel transmit on another link an altered version of the intercepted I/O stream to another control unit, which is responsible for holding a mirrored version of the data. The altered version could have the same data as that on the one link but have new frame headers injected at appropriate points in the I/O stream. Moreover, the intelligent splitter may improve the functionality of extended functions such as mirroring as well. The alterations to the I/O stream to the mirroring control unit may include changes to the control information of the I/O stream, for example, to address the mirroring control instead of the primary unit. But the alterations may also include changes to the data itself, including formatting, filtering and translating. A host may be connected to potentially several intelligent splitters to implement extended functions cooperatively. Among other things, the host may be used to configure the splitter to perform the mirroring (or other) operation at a physical level of addressing, though the host may receive requests expressed at a logical level. The host may then map the logical name to physical addresses and configure the splitter accordingly. The host may also instruct the splitter to create and send streams independently of any I/O streams passing through the splitter. This created I/O stream may correspond to an entire CCW in ESCON contexts.

I/O system supporting extended functions and method therefor

A method of creating a snapshot copy of data stored on a first direct access storage device is described. It includes the acts of receiving information identifying a set of data that is to be copied from the first direct access storage device and mapping destination locations in a second direct access storage device for each element of the set. The destination locations are in a sequence emulating a tape copy. The method also includes the acts of iterating through the set of data. For the each element of the set, the method of the present invention also includes the acts of determining if the element has already been copied to the second direct access storage device, and, if the element has not already been copied, then copying the element to its mapped location in the second direct access storage device. A corresponding system is also described.

Data backup method and system using snapshot and virtual tape

A method and system are disclosed for enhanced efficiency of backup copying of designated datasets stored within a plurality of storage devices coupled to the data processing system via a storage subsystem control unit having subsystem memory therein. Application execution within the data processing system is temporarily suspended long enough to form a dataset logical-to-physical system address concordance to be utilized to administer copying of the designated dataset. Thereafter, application initiated updates to uncopied portions of the designated datasets are temporarily deferred until sidefiles of the affected portions of the designated datasets are written to subsystem memory. The updates are then written to the storage subsystem. Portions of the designated datasets are then accessed and copied from the storage subsystem on a scheduled or opportunistic basis utilizing selected data retrieval command sequences. A sidefile status query is appended to selected data retrieval command sequences and the presence of data within the subsystem memory is determined without the necessity of additional communications between the data processing system and the storage subsystem. The sidefiles are then accessed and copied. Copied portions of the designated datasets and sidefiles are then copied to alternate storage locations in a backup copy order defined by the address concordance.

Method and system for sidefile status polling in a time zero backup copy process

A method and apparatus for improving storage controller throughput when servicing non-specific read requests. Throughput is increased by enabling the storage controller to service non-specific read requests issued against a device address which is not the same as the device address associated with the data that the non-specific read is requesting. The device address associated with the data is thus free to be used for another I/O operation. When the device address used by the non-specific read is a non-busy type (that is, the device and/or data is not locked) then the throughput improvement is obtained by increasing the number of data requests that may be concurrently handled by the storage controller.

Locking a non-busy device for accessing a data record stored on another

A data backup copying session on a data processing system is secured responsive to initiation of the data backup session by an application executing on a processing unit by generating a unique identifier for the data backup session. Thereafter, all member paths of a group of paths designated by the processing unit for communication between itself and the first storage subsystem are identified and associated with the data backup session. Access to the session is thereafter allowed only along a member path of the group of paths associated with the data backup session. The system and method of the invention further provide for fault recovery and protection against excessive demand on storage control unit memory.

Method and system for time zero backup session security

A method and system for efficiently accessing desired datasets among multiple datasets which are stored at specific data addresses within multiple storage subsystems which are coupled to a host system via a storage subsystem controller and a data channel. A data request is transmitted from the host system to the storage subsystems via the data channel. The data request specifies non-address attributes for desired datasets, such as boundary addresses for large data extents including many datasets or a request for all datasets modified since the occurrence of a specified event. The data request is then processed at the storage subsystem controller to determine a data address for each dataset within the storage subsystem which possess the desired attributes. Thereafter, the desired datasets are transmitted via the data channel to the host system in association with a specific address for each dataset. A selected status message is transmitted from the storage subsystem controller when no more datasets are located which possess the desired attributes. In this manner, the retrieval of data from a storage subsystem is greatly enhanced.

Method and system for non-specific address data retrieval in a data

A method and system are disclosed for permitting high concurrency of access during backup copying of designated data stored within a storage subsystem which includes multiple storage devices coupled to the data processing system via a storage subsystem control unit having subsystem memory therein. Data within each storage device is accessed utilizing a Unique Control Block (UCB), which identifies a selected storage device, and an associated data retrieval command sequence which identifies the data to be accessed. Portions of the data copied to subsystem memory within the subsystem storage control unit as sidefiles from a first storage device may be accessed utilizing a Unique Control Block (UCB) associated with an alternate storage device by associating a selected data retrieval command sequence therewith which identifies the data as stored within the subsystem memory. In this manner, data from a first storage device may be accessed utilizing an alternate Unique Control Block (UCB), permitting concurrent access of data utilizing the Unique Control Block (UCB) associated with the first storage device.

Growing community of inventors

Haifa, Israel

Alexander Winokur