Browse Prior Art Database

Disk Adapter Diagnostic Aid

IP.com Disclosure Number: IPCOM000050789D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Ott, WB: AUTHOR [+2]

Abstract

An isolation of system adapter failures from disk drive failures is a chronic problem when troubleshooting disk storage systems. Most disk storage systems incorporate redundancy in the form of extra check characters generated by the system adapter and attached to each written record on the file. Whenever a record is read from the disk, the system adapter regenerates the check characters using the data read and compares them to the appended check characters to detect disk drive errors.

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Disk Adapter Diagnostic Aid

An isolation of system adapter failures from disk drive failures is a chronic problem when troubleshooting disk storage systems. Most disk storage systems incorporate redundancy in the form of extra check characters generated by the system adapter and attached to each written record on the file. Whenever a record is read from the disk, the system adapter regenerates the check characters using the data read and compares them to the appended check characters to detect disk drive errors.

It is possible to improve the serviceability of the disk system by making the check characters available back to the system processor. The processor may then verify that, in fact, correct data was supplied to the disk drive by the system adapter by comparing these generator check characters to ones precalculated. Further, it is possible to include this feature in such a way that the check characters are returned to the processor through the normal disk read channel, thereby verifying its operability as well.

Referring to the figure, a normal disk adapter with an additional feature is shown. The serial written data is available to replace the serial read data as input to the shift register. After data is written to the disk, the generator check characters are written. While the check characters are being written, the shift register is available and is used to deserialize the check characters and send them back to the processor in exactly the same way as no...