Abstract: Embodiments of the present invention provide systems and methods of centralized mapping of media library partitions. According to one embodiment, the present invention can include a first controller connected to a data transport element of a media library and a second controller connected to a media changer of the media library. The first controller can receive a command from a host application based on a media library partition presented to that host and forward the command to the second controller. The second controller can receive the command from the first controller, translate logical addresses referenced in the command to physical addresses and forward the command to the media changer. The second controller, can also prioritize the command on a FIFO basis or according to other prioritization scheme known in the art.

Abstract: Systems and methods for synchronizing digital communications links, wherein one embodiment implemented in a receiver of a communications link comprises a shift register coupled to a transmission medium to receive synchronization data and a feedback circuit coupled to the shift register, wherein one or more cells of the shift register are configured to alternatively accept as input either a bit from a preceding cell or a received bit of synchronization data. The first occurs prior to synchronization, while the second occurs after synchronization. A counter is used to assert a signal indicating that the transmitter and receiver are synchronized.

Abstract: Systems and methods for coordinating the interoperability of devices in a network are disclosed. Embodiments of the present invention may provide the ability for a host device in a storage network to inquire as to the capabilities of a storage device in a storage network. A routing device between the host and the storage device may receive a response, and if the routing device has a higher capability than the storage device the routing device may convert the response to a response that reflects the higher capabilities of the routing device before sending the response on to the host. However, if the storage device has a higher capability than the routing device, the routing device may pass the response through to the host unaltered.

Abstract: According to one embodiment of the present invention, a controller that partitions a media library for multiple host applications can, for each partition, assign a base element address for an element type and associate physical element addresses for elements of an element type with an index value. For a partition, the logical element address corresponding to a physical element address for an element can be determined by adding the index number associated with the physical element address to the base element address for that element type. The physical element address corresponding to a logical element address for an element can be determined by subtracting the base element address for the element type from the logical element address for the element. The result of subtracting the base element address from the logical element address is an index value for which the associated physical element address can be found.

Abstract: Systems and methods for performing error recovery in a system utilizing redundant communication links. In one embodiment, a host device is coupled to a sequential device such as a tape drive by a pair of Fiber Channel links. The host is configured to associate an identifier with each command. Upon detecting a failure of the transmission of the command via the first link, the host re-transmits the command via the second link. When the link failure is detected, the status of the last command transmitted before the failure is requested. After receiving the status of the command, a request that recovery start (possibly at a point indicated by the status information) is transmitted to the sequential device. If the recovery request is accepted, performance of the command is completed.

Abstract: Embodiments of a routing device for coordinating the interoperability of devices with varying capabilities that send and/or receive commands in a storage network are disclosed. A host device in the storage network may inquire the capabilities of a storage device in a storage network. A routing device may receive a response from the storage device and pass the response through to the host unaltered or may alter the response to reflect the higher or lower capabilities of the routing device before sending the response to the host.

Abstract: A storage router (56) and storage network (50) provide virtual local storage on remote SCSI storage devices (60, 62, 64) to Fiber Channel devices. A plurality of Fiber Channel devices, such as workstations (58), are connected to a Fiber Channel transport medium (52), and a plurality of SCSI storage devices (60, 62, 64) are connected to a SCSI bus transport medium (54). The storage router (56) interfaces between the Fiber Channel transport medium (52) and the SCSI bus transport medium (54). The storage router (56) maps between the workstations (58) and the SCSI storage devices (60, 62, 64) and implements access controls for storage space on the SCSI storage devices (60, 62, 64). The storage router (56) then allows access from the workstations (58) to the SCSI storage devices (60, 62, 64) using native low level, block protocol in accordance with the mapping and the access controls.

Abstract: A storage router (56) and storage network (50) provide virtual local storage on remote SCSI storage devices (60, 62, 64) to Fibre Channel devices. A plurality of Fibre Channel devices, such as workstations (58), are connected to a Fibre Channel transport medium (52), and a plurality of SCSI storage devices (60, 62, 64) are connected to a SCSI bus transport medium (54) The storage router (56) interfaces between the Fibre Channel transport medium (52) and the SCSI bus transport medium (54). The storage router (56) maps between the workstations (58) and the SCSI storage devices (60, 62, 64) and implements access controls for storage space on the SCSI storage devices (60, 62, 64). The storage router (56) then allows access from the workstations (58) to the SCSI storage devices (60, 62, 64) using native low level, block protocol in accordance with the mapping and the access controls.

Abstract: A storage router (56) and storage network (50) provide virtual local storage on remote SCSI storage devices (60, 62, 64) to Fibre Channel devices. A plurality of Fibre Channel devices, such as workstations (58), are connected to a Fibre Channel transport medium (52), and a plurality of SCSI storage devices (60, 62, 64) are connected to a SCSI bus transport medium (54) The storage router (56) interfaces between the Fibre Channel transport medium (52) and the SCSI bus transport medium (54). The storage router (56) maps between the workstations (58) and the SCSI storage devices (60, 62, 64) and implements access controls for storage space on the SCSI storage devices (60, 62, 64). The storage router (56) then allows access from the workstations (58) to the SCSI storage devices (60, 62, 64) using native low level, block protocol in accordance with the mapping and the access controls.

Abstract: A system and method for storing header information in parallel with corresponding frames of data, wherein the frames of data are stored in a first-in-first-out buffer and wherein the header information is accessed to make routing decisions for the frames of data while avoiding having to read the frames out of the buffer. In one embodiment, this buffer system is implemented in a port of a network switch. Receive logic in the port stores frames of data in the storage elements of a FIFO buffer and concurrently snoops on the frame data to obtain header information. The header information is stored in a buffer separate from the FIFO that stores the frames. The header information can be read from the header buffer rather than the frame buffer. A routing decision for each frame can be made before a previous frame is completely read out of the frame FIFO, hence before the corresponding frame is ready to be transmitted.

Abstract: Systems and methods for distributing management information in a computing system over existing power are disclosed. These systems and methods may eliminate the need for a separate physical network to distribute management information in the computer system and the commensurate physical hardware need to implement these networks. A management system may place a management communication on a physical transport medium. This management communication may then be placed on the power lines used to power the various components of the computing system and distributed to the various components along these power lines, where it may be received by its intended recipient and acted upon if necessary.

Abstract: A system and method for servicing inquiry commands, wherein inquiry data is stored in a memory and if an inquiry command for a target device is received while the target device is busy processing another command, the stored inquiry data is returned in response to the command. In one embodiment, a router contains a memory for storing static inquiry data corresponding to each of a plurality of sequential devices connected thereto. The first time a host sends an inquiry command to one of the sequential devices, the router routes the command to the target device and stores the data returned by the device. Subsequent inquiry commands are serviced by passing the command through to the target device if it is not busy, or returning inquiry data from the router's memory if the target device is busy processing another command.

Abstract: A storage router (56) and storage network (50) provide virtual local storage on remote SCSI storage devices (60, 62, 64) to Fibre Channel devices. A plurality of Fibre Channel devices, such as workstations (58), are connected to a Fibre Channel transport medium (52), and a plurality of SCSI storage devices (60, 62, 64) are connected to a SCSI bus transport medium (54) The storage router (56) interfaces between the Fibre Channel transport medium (52) and the SCSI bus transport medium (54). The storage router (56) maps between the workstations (58) and the SCSI storage devices (60, 62, 64) and implements access controls for storage space on the SCSI storage devices (60, 62, 64). The storage router (56) then allows access from the workstations (58) to the SCSI storage devices (60, 62, 64) using native low level, block protocol in accordance with the mapping and the access controls.

Abstract: Systems and methods for coordinating the interoperability of devices with varying capabilities are disclosed. A host device may inquire as to the capabilities of a storage device in a storage network. A routing device may receive this response, and if the routing device has a higher capability than the storage device the routing device may convert the response to a response that reflects the higher capabilities of the routing device before sending the response on to the host. However, if the storage device has a higher capability than the routing device, the routing device may pass the response through to the host unaltered so the host may take advantage of the capabilities of the storage device. Alternatively, the router may convert the response to a response that reflects the lower capabilities of the routing device before sending the response on to the host.

Abstract: A method and system are disclosed for processing multiple commands to a streaming target device through a SCSI router in a Fibre Channel network provisioned with one or more Fiber Channel hosts. The system and method are implemented in the SCSI router and include creating a FIFO queue, receiving a first command from one of the Fibre Channel hosts in the Fibre Channel network, and forwarding the first command to the streaming target device. When a subsequent command is issued to the streaming target device, the SCSI router can receive the subsequent command and determine whether the streaming target device has completed execution of the previous command. If the streaming target device has completed execution of the previous command, the subsequent command can be forwarded to the streaming target device. If the streaming target device has not completed executing the previous command, the subsequent command can instead be placed in the FIFO queue.

Abstract: Systems and methods for performing multi-threaded backups and restores. In one embodiment, a log is maintained to record the source of write commands, and the order in which blocks of data are written to a sequential storage device. The source identification of the write command may consist of such identifiers as a protocol dependent Host ID, the extended-copy-specification-defined List ID, a time stamp, and the size of the backup medium block written. The order in which the data is written to the backup medium can be identified with these same Host ID and List ID numbers. When it is desired to restore data corresponding to one of the threads, the desired blocks of data can be identified in the log, and the preceding blocks stored on the backup medium can be skipped.

Abstract: Systems and methods for reducing the number of unit attentions provided to a set of initiator devices by eliminating unnecessary unit attentions from queues in which unit attentions for each of the initiator devices are stored. In one embodiment, a system comprises a processor and a memory implemented in a router that is coupled between a target device and multiple initiator devices. As each unit attention is generated by the target device, it is forwarded to the initiator device that prompted the unit attention, and is stored in a queue for each of the other initiator devices. Periodically, the queues are examined to determine whether any of the unit attentions stored therein are unnecessary. One or more of the unit attentions that are determined to be unnecessary may be eliminated from the respective queues, reducing the number of unit attentions that are provided to the respective initiator devices.

Abstract: A storage router and storage network provide virtual local storage on remote storage devices to Fiber Channel devices. A plurality of Fiber Channel devices, such as workstations, are connected to a Fiber Channel transport medium, and a plurality of storage devices are connected to a second Fiber Channel transport medium. The storage router interfaces between the Fiber Channel transport media. The storage router maps between the workstations and the storage devices and implements access controls for storage space on the storage devices. The storage router then allows access from the workstations to the storage devices using native low level, block protocol in accordance with the mapping and the access controls.

Abstract: Systems and methods for performing error recovery in a system utilizing redundant communication links. In one embodiment, a host device is coupled to a sequential device such as a tape drive by a pair of Fibre Channel links. The host is configured to associate an identifier with each command. Upon detecting a failure of the transmission of the command via the first link, the host re-transmits the command via the second link. When the link failure is detected, the status of the last command transmitted before the failure is requested. After receiving the status of the command, a request that recovery start (possibly at a point indicated by the status information) is transmitted to the sequential device. If the recovery request is accepted, performance of the command is completed.

Abstract: A system and method for compensating for differences between a recovered receive clock and an internal transmit clock in an elastic buffer and thereby preventing corruption of data. In one embodiment, the system comprises a circularly accessed buffer coupled to read and write logic. The read and write logic read and write to locations within the circular buffer as indicated by respective read and write pointers. The system further comprises control logic which compares the pointers to determine whether the buffer is approaching an underflow or overflow condition and adds or deletes fill words between frames of data to compensate for the underflow or overflow condition. In one embodiment, the system includes fill word logic which is configured to add a fill word bit to each received word and to set or clear the fill word bit to indicate whether or not the corresponding word is a fill word.