Compaq Computer Corporation, Inc.

Hewlett-packard Development Company, L.p.

David L Grant

E David Neufeld

Stephen M Schultz

David L Flower

David S Schmenk

Robert S Gready

Raymond A Ritter

John E Dimitroff

Eugene E Freeman

John Dimitroff

Gary L Phillips

Zuohui Zhang

A computer system and storage management method for routing data between peer-level storage units. The computer system includes a first storage unit (e.g., disk drive) and an intelligent controller connected to a storage area network. The intelligent controller is also connected to a second storage unit (e.g., tape drive). The computer system further includes a host (server and/or workstation) having an application module for generating and transmitting a command to the intelligent controller by way of the storage area network or a system network. In response to the transmitted command, the intelligent controller routes data between the first storage unit and the second storage unit using the storage area network while bypassing the host.

Computer system and method for transferring data between multiple peer-level storage units

For use with a computer system having an intelligent mass storage disk array subsystem, including a microprocessor controller, a method for the distribution of data within the disk array based upon logical commands issued by the computer system. The disk controller reads a logical command and translates the commands into multiple drive specific commands, including drive physical parameter information such as head, sector and cylinder selection. The calculation of these physical parameters is based upon a number of factors including the operating system installed in the computer system, the type of interleave scheme, if any, specified by the computer system configuration, and disk specific parameters. The physical drive requests are then placed in a queue and executed by the microprocessor controller. The method also encompasses a method for creating a disk array configuration to be loaded on all disks within the array based on existing valid disk array information and configuration information maintained by the computer system.

Data distribution in a disk array

A cascaded removable media data storage system includes a first level enhanced removable media data storage system controller connected to a host or server computer network. Connected in parallel to the enhanced first level removable media data storage system controller are at least two enhanced second level removable media data storage system controllers. Each enhanced second level removable media data storage system controllers is connected to a mirrored group of removable media data storage units.

Cascaded removable media data storage system

A network provides a method of virtualizing SCSI semantics onto a non-SCSI transport medium. The network includes a plurality of hosts or initiators, a SCSI bus coupled to a plurality of SCSI devices, and a bridge having a non-SCSI front end coupled to the non-SCSI transport medium and a SCSI back end coupled to the SCSI bus. The bridge provides firmware for performing various techniques for virtualizing certain SCSI semantics to ensure support (proper operation) of the plurality of SCSI devices. Examples of SCSI semantics for virtualizing SCSI-2 semantics onto a Fibre Channel interconnect medium (a non-SCSI-2 transport medium) include reserve/release support, unit attention support, the non-tagged command processing support for the initiators. Reserve/release support is virtualized by implementing virtual command responses to the RESERVE and RELEASE SCSI-2 command using a table for storing Fibre Channel world wide names (WWN) and the arbitrated loop address (ALPA) for the plurality of initiators. Virtual unit attention support is achieved by maintaining alist of initiators and status flags to determine when a unit attention condition needs to be sent to a particular initiator. When a combination of tagged and untagged commands is detected which would violate the rules for mixing such commands on the back-end SCSI bus, any command(s) that would result in the rule violation will be held within the bridge until the currently outstanding conflicting commands have completed.

Supporting a SCSI device on a non-SCSI transport medium of a network

Method for developing physical disk drive specific commands from logical

A bus master interface command protocol for use with a computer system having an intelligent mass storage disk array subsystem, including a bus master and microprocessor controller. The command protocol permits the computer system to issue disk array commands to the controller at a logical level without having to issue disk specific commands. The disk array subsystem microprocessor controller reads the logical commands, translates the commands into smaller disk specific commands, and queues the disk specific commands for processing. Upon completion of the logical command, the bus master controller asserts control over the computer system bus and manages the transfer of data to or from the computer system memory. The management of the disk array subsystem and the transfer of data is effectively off-loaded from the system processor permitting more efficient use of the processor.

Method for controlling disk array operations by receiving logical disk

A method is disclosed for restoring apparently lost files on a computer whose directory file entries have been corrupted. In particular, the method includes an improved technique for locating initial or head clusters of files. An array is initialized to indicate that each element of a file allocation table (FAT) corresponds to a head cluster. Each element of the FAT is then examined, and the array is updated to reflect accurately those elements that correspond to non-head clusters. When all elements of the FAT have been so examined, the array is scanned to build a list of head cluster numbers.

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Houston, TX, United States of America

David L Grant