Abstract: A computing system includes a computer executing an emulated operating system, the emulated operating system including a multichannel control unit; a plurality of virtual drives accessible to the emulated operating system; and a communication channel, the communication channel connecting the multichannel control unit and the virtual drives through one or more virtual channels. The multichannel control unit sends a first data access request to a virtual drive through the first virtual channel of the communication channel, the multichannel control unit sends a second data access request to a virtual drive through the second virtual channel of the communication channel.

Abstract: A computing system includes a computer executing an emulated operating system, the emulated operating system including a multichannel control unit; a plurality of virtual drives accessible to the emulated operating system; and a communication channel, the communication channel connecting the multichannel control unit and the virtual drives through one or more virtual channels. The multichannel control unit sends a first data access request to a virtual drive through the first virtual channel of the communication channel, the multichannel control unit sends a second data access request to a virtual drive through the second virtual channel of the communication channel.

Abstract: A method and system for providing a plurality of host systems shared access to data files from a file server. The method includes monitoring a control file for updates, the control file located within a corresponding host directory located within the file server; receiving a request for access to a data file stored on the file server, the access request being written to the control file, the access request including a requested data file operation; performing the requested data file operation in response to the control file being updated with the access request; creating a status file in the host directory in which the requested data file operation was performed upon completion of the requested data file operation; writing status data in the status file, the status data including a result of the performance of the requested data file operation; and allowing access to the host directory in which the requested data file operation was performed in response to the status data being written to the status file.

Abstract: A method includes determining, by a processor, whether a program check condition exists. The method further includes determining, by the processor, whether a lock descriptor of a lock in a file lock table satisfies an unlocking condition. The method further includes releasing, by the processor, the lock by setting the lock descriptor's host identifier as zero. The method further includes determining, by the processor, whether any lock in the file lock table satisfies a lock conflict condition. The method further includes determining, by the processor, whether the file lock table includes any lock descriptor that satisfies a locking condition. The method further includes creating, by the processor, a new lock using the lock descriptor that satisfies the locking condition.

Abstract: A method and system for providing a plurality of host systems shared access to data files from a file server. The method includes monitoring a control file for updates, the control file located within a corresponding host directory located within the file server; receiving a request for access to a data file stored on the file server, the access request being written to the control file, the access request including a requested data file operation; performing the requested data file operation in response to the control file being updated with the access request; creating a status file in the host directory in which the requested data file operation was performed upon completion of the requested data file operation; writing status data in the status file, the status data including a result of the performance of the requested data file operation; and allowing access to the host directory in which the requested data file operation was performed in response to the status data being written to the status file.

Abstract: A method includes determining, by a processor, whether a program check condition exists. The method further includes determining, by the processor, whether a lock descriptor of a lock in a file lock table satisfies an unlocking condition. The method further includes releasing, by the processor, the lock by setting the lock descriptor's host identifier as zero. The method further includes determining, by the processor, whether any lock in the file lock table satisfies a lock conflict condition. The method further includes determining, by the processor, whether the file lock table includes any lock descriptor that satisfies a locking condition. The method further includes creating, by the processor, a new lock using the lock descriptor that satisfies the locking condition.

Abstract: Systems and methods for performing data input/output (I/O) operations using a computer network communications link are described. A method may include assigning a block of virtual addresses for usage with at least one computer network communications link. The method may also include registering the entire block of virtual addresses prior to an operating system partition performing I/O operations using the at least one computer network communications link, wherein registering comprises setting a plurality of virtual page frame numbers of the block of virtual addresses to point to distinct pages of physical memory. In some embodiments, one or more I/O operations may be performed using the at least one computer network communications link and the registered block of virtual addresses.

Abstract: Systems and methods for performing data input/output (I/O) operations using a computer network communications link are described. A method may include assigning a block of virtual addresses for usage with at least one computer network communications link. The method may also include registering the entire block of virtual addresses prior to an operating system partition performing I/O operations using the at least one computer network communications link, wherein registering comprises setting a plurality of virtual page frame numbers of the block of virtual addresses to point to distinct pages of physical memory. In some embodiments, one or more I/O operations may be performed using the at least one computer network communications link and the registered block of virtual addresses.

Abstract: A legacy operating system (OS) of a type generally associated with an enterprise-level, legacy data processing platform such as a mainframe is instead provided on a commodity data processing platform such as a personal computer. The legacy OS is adapted to communicate with legacy IOP devices of the type generally associated with the legacy platform to provide data protection mechanisms for legacy data. To initiate an I/O operation, a commodity OS executing on the commodity platform allocates a memory buffer and provides the virtual buffer address to the legacy OS. The legacy OS uses this address to construct a description of an I/O operation to be performed using the buffer. The description is then translated from one referencing a first memory page size in virtual address space into a description referencing a different page size in physical address space so that legacy IOP can complete the operation.

Abstract: The various embodiments of the invention relate to analyzing operations of an emulated input-output processor. Instructions native to the first type of instruction processor are emulated on a second-type instruction processor. The instruction processor emulator executes an operating system that includes instructions native to the first type of instruction processor. The operating system includes instructions that write input/output (IO) requests to the memory arrangement in response to IO functions invoked by a program. An IOP emulator that is executable on the second-type processor emulates IOP processing of IO requests from the memory arrangement. The IOP emulator maintains in the memory arrangement a first set of data structures used in processing the IO requests. State data currently contained in the data structures is stored on a retentive storage device, and in response to user input controls, the state data is read from retentive storage and displayed.

Abstract: An apparatus for and method of enhancing reliability within a cluster lock processing system having a relatively large number of commodity cluster instruction processors which are managed by a cluster lock manager. Because the commodity processors have virtually no system viability features such as memory protection, failure recovery, etc., the cluster/lock processors assume the responsibility for providing these functions. The low cost of the commodity cluster instruction processors makes the system almost linearly scalable. The cluster/locking, caching, and mass storage accessing functions are fully integrated into a single hardware platform which performs the role of the master. Upon failure of this hardware platform, a second redundant hardware platform converts from slave to master role. The logic for the failure detection and role swapping is placed within software, which can run as an application under a commonly available operating system.

Abstract: An apparatus for and method of implementing a cluster lock processing system having a relatively large number of commodity cluster instruction processors which are managed by a highly scalable, off the shelf communication processor. Because the commodity processors have virtually no system viability features such as memory protection, failure recovery, etc., the communication processor assumes the responsibility for providing these functions. The low cost of the commodity cluster instruction processors makes the system almost linearly scalable. Furthermore, having a fully scalable communication processor ensures a completely scalable system. The cluster/locking, caching, and mass storage accessing functions are fully integrated into a single hardware platform.

Abstract: A system and method for testing I/O components without requiring initiation of the test I/O requests from the operating system via the instruction stream. An I/O system facilitates I/O operations between a processing system and I/O devices during normal I/O processing. An exerciser initiation queue is established, which corresponds to an operating initiation queue used during normal I/O processing. The I/O system is configured to monitor for test I/O requests on the exerciser initiation queue in lieu of monitoring for standard I/O requests on the operating initiation queue. A testing module enters the test I/O requests on the exerciser initiation queue in a format analogous to standard I/O requests entered on the operating initiation queue during normal I/O processing. The test I/O requests on the exerciser initiation queue are processed via the I/O system. Upon I/O completion, status may be returned to the testing module for processing of test results.

Abstract: A method of and apparatus for efficiently and effectively coupling a newly designed peripheral device to a legacy data processing system. The approach utilizes emulation of a SCSI tape device by a SCSI DVD device. Through device emulation, system-wide modifications are minimized.

Abstract: A system and method for processing I/O requests in a computing system. I/O packets are created via an operating system associated with the computing system, where the I/O packets include I/O transaction information. The I/O packets are made accessible to an I/O system. A command for a channel type connecting a target I/O component to the I/O system is constructed, where this command construction is based on the I/O transaction information provided in the I/O packet, and based on physical aspects of the target I/O component and channel type provided independently of the I/O packet. The constructed command is issued to the target I/O component in accordance with the channel type.