International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Jeffrey Richards Hester

Shad Henry Thorstenson

Brian Lee Morger

Michael James Miller

A SCSI ID of a SCSI initiator device that has won an arbitration is identified on a SCSI bus and stored in a register at a SCSI device. Subsequently, a SCSI ID of a selected SCSI target device which was selected by the SCSI initiator device is identified on the SCSI bus and compared with the SCSI ID in the register. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are different, a SCSI command from the SCSI initiator device is processed by the selected SCSI target device. If the SCSI ID of the selected SCSI target device and the SCSI ID stored in the register are the same, the selected SCSI target device refrains from processing the SCSI command from the SCSI initiator device.

Methods and apparatus for improving data integrity for small computer system interface (SCSI) devices

A peripheral device (which is preferably a disk drive) can automatically collect trace data upon detecting certain error conditions. The peripheral device has the ability to selectively alter the range of state data collected in a trace depending on the error type. Preferably, the device includes a programmable processor executing a control program. A set of trace switches, each enabling a corresponding set of trace points, can be independently set by the control program. An error trace identification table identifies, for each error type, a corresponding set of trace switches. If an error is encountered, the trace switches corresponding to the error type are determined from the table, and the switches are set accordingly. In another invention aspect, a set of trap switches in the device can be set to trap on the occurrence of a specific error type, thereby supporting a more detailed error analysis.

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Mantorville, MN, United States of America

Jeffrey Richards Hester