Max V Johnson

US Patent:

6412045, Jun 25, 2002

Filed:

May 23, 1995

Appl. No.:

08/447594

Inventors:

Rodney A. DeKoning - Wichita KS
Donald R. Humlicek - Wichita KS
Max L. Johnson - Wichita KS
Curtis W. Rink - Wichita KS

Assignee:

LSI Logic Corporation - Milpitas CA

International Classification:

G06F 1200

US Classification:

711135, 711133

Abstract:

An apparatus and method is disclosed which enables a host computer to adjust the caching strategy used for writing its write request data to storage media during execution of various software applications. The method includes the step of generating a caching-flushing parameter in the host computer. The cache flushing parameter is then transferred from the host computer to a controller which has a cache memory. Thereafter, a quantity of write request data is written from the cache memory to a storage medium in accordance with the cache-flushing parameter.

US Patent:

6898666, May 24, 2005

Filed:

Nov 1, 2001

Appl. No.:

10/004208

Inventors:

Russell J. Henry - Wichita KS, US
Max L. Johnson - Wichita KS, US
Bret Weber - Wichita KS, US
Dennis E. Gates - Wichita KS, US

Assignee:

LSI Logic Corporation - Milpitas CA

International Classification:

G06F012/00

US Classification:

711114, 711141, 711203

Abstract:

A method of increasing computer system bandwidth for computer system having two or more memory complexes is disclosed in which exclusive OR operations are performed on the data from the data regions to generate parity information which is stored in the same single cache pool as the data regions. By using a single cache pool for related data regions, bandwidth and performance are improved.

US Patent:

55881106, Dec 24, 1996

Filed:

May 23, 1995

Appl. No.:

8/447377

Inventors:

Rodney A. DeKoning - Wichita KS
Donald R. Humlicek - Wichita KS
Max L. Johnson - Wichita KS

Assignee:

Symbios Logic Inc. - Fort Collins CO

International Classification:

G06F 1314

US Classification:

39518203

Abstract:

A method of insuring recovery of a quantity write request data in a storage device having a plurality of controllers includes the steps of (1) providing a primary controller for storing the write request data received from a host device, (2) providing an alternate controller having a memory area allocated for use by the primary controller, (3) maintaining a first control block in the primary controller for indicating status of the write request data stored in the primary controller, and (4) maintaining a second control block in the alternate controller for indicating status of the write request data stored in the primary controller.

US Patent:

57784264, Jul 7, 1998

Filed:

Oct 23, 1995

Appl. No.:

8/546861

Inventors:

Rodney A. DeKoning - Wichita KS
Donald R. Humlicek - Wichita KS
Max L. Johnson - Wichita KS
Curtis W. Rink - Wichita KS

Assignee:

Symbios, Inc. - Fort Collins CO

International Classification:

G06F 1300

US Classification:

711122

Abstract:

Methods and associated data structures operable in a RAID subsystem to improve I/O performance. A two level cache data structure and associated methods are implemented with a RAID controller. The lower level cache comprises buffers holding recently utilized blocks of the disk devices. The upper level cache records which blocks are present in the lower level cache for each stripe in the RAID level 5 configuration. The upper level cache serves to reduce the overhead processing required of the RAID controller to determine which blocks are present in the lower level cache. Having more rapid access to this information by lowering the processing overhead enables the present invention to rapidly select between different write techniques to post data and error blocks from low level cache to the disk array. A RMW write technique is used to post data and error checking blocks to disk when insufficient information reside in the lower level cache. A faster Full Write technique (also referred to as Stripe Write) is used to post data and error checking blocks to disk when all required, related blocks are resident in the lower level cache.

US Patent:

60676353, May 23, 2000

Filed:

Sep 4, 1997

Appl. No.:

8/923228

Inventors:

Rodney A. DeKoning - Wichita KS
Donald R. Humlicek - Wichita KS
Max L. Johnson - Wichita KS
Curtis W. Rink - Wichita KS

Assignee:

LSI Logic Corporation - Milpitas CA

International Classification:

G06F 1100

US Classification:

714 6

Abstract:

The invention relates to a method and apparatus for maintaining data/parity consistency in a RAID data storage system. The invention utilizes reserved disk storage space in the RAID array to log data necessary to restore data/parity consistency should an interruption event, such as a power failure, corrupt the data stored in a particular redundancy group. In one embodiment, the invention logs new data and new parity information to the reserved disk storage space before the new data and new parity information are written to the appropriate locations in the associated redundancy group. In this way, if an interruption event occurs when either the new data or the new parity information has already been written to the redundancy group but the other has not, the corresponding data and parity information stored in the reserved disk storage space can be used to restore data/parity consistency after the event has ended.

US Patent:

57617058, Jun 2, 1998

Filed:

Apr 4, 1996

Appl. No.:

8/630906

Inventors:

Rodney A. DeKoning - Wichita KS
Donald R. Humlicek - Wichita KS
Max L. Johnson - Wichita KS

Assignee:

Symbios, Inc. - Fort Collins CO

International Classification:

G06F 1208
G06F 1316
G06F 1114

US Classification:

711113

Abstract:

Methods and associated apparatus operable in a RAID subsystem having redundant disk array controllers to assure dual, redundant cache consistency while permitting operation of the RAID subsystem in response to host computer I/O requests. The methods and apparatus of the present invention provide for a process of initializing the redundant disk array controllers in response to a power-on reset cycle (or other similar reset cycles). The first controller partially initializes for processing of host requests then awaits the partial initialization of the second controller. After a brief timeout awaiting the second controller, or in response to an erroneous initialization of the second controller, the first controller configures itself to perform host computer I/O requests in a write-through mode (bypassing cache operations) until the second controller eventually initializes. Once both controller are initialized, the redundant caches are synchronized. Finally, the initialized controllers having synchronized the redundant caches begin normal, mirrored, redundant operation.

US Patent:

57872422, Jul 28, 1998

Filed:

Dec 29, 1995

Appl. No.:

8/580566

Inventors:

Rodney A. DeKoning - Wichita KS
Donald R. Humlicek - Wichita KS
Max L. Johnson - Wichita KS

Assignee:

Symbios Logic Inc. - Fort Collins CO

International Classification:

G06F 1100
G06F 1200

US Classification:

39518203

Abstract:

Methods and apparatus for moving pinned data corresponding to a temporarily dead RAID device between the cache memory of a RAID subsystem and a log area. In response to detection of a dead RAID device within a RAID subsystem, the methods of the present invention move any pinned data from the cache memory of the RAID controller to a log area preferably allocated on the disk space of one or more operational RAID devices within the subsystem. In response to revival of the dead RAID device methods of the present invention restore the logged, pinned data from the log area of the operational RAID device(s) to the cache memory as dirty data ready for posting to the revived RAID device. The log area may be either permanently allocated within the RAID subsystem, or may be dynamically allocated in response to recognition of the dead RAID device and freed in response to revival of the RAID device.