Stephen Sicola

US Patent:

6356979, Mar 12, 2002

Filed:

May 17, 1999

Appl. No.:

09/312944

Inventors:

Stephen J. Sicola - Monument CO
Michael D. Walker - Colorado Springs CO
James E. Pherson - Colorado Springs CO

Assignee:

Compaq Computer Corporation - Houston TX

International Classification:

G06F 1200

US Classification:

711114, 711163

Abstract:

A storage system capable of selectively presenting logical units to one or more host computing systems. The storage system comprises one or more persistent storage devices arranged as logical units; an array controller controlling and coordinating the operations of the persistent storage devices; a memory accessible by the array controller; and a configuration table stored in the memory, the configuration table containing one or more entries governing the interactions between the logical units and the one or more host computing systems. The configuration table contains an entry for each logical unit which the array controller accesses to determine if a particular logical unit should communicate with a particular one of the host computing systems, an entry for each logical unit which the array controller accesses to determine if a particular logical unit should communicate with a particular one of the host computing systems using an internal offset for a logical unit number, and an entry for each logical unit which the array controller accesses to determine if a particular logical unit should communicate with a particular one of the host computing systems using a predetermined host mode.

US Patent:

6571324, May 27, 2003

Filed:

Jun 26, 1997

Appl. No.:

08/883381

Inventors:

Susan G. Elkington - Colorado Springs CO
Stephen J. Sicola - Monument CO
Wayne H. Umland - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1208

US Classification:

711162, 711120, 711143, 714 6

Abstract:

A warmswap operation to replace modules in a mirrored cache system has been accomplished by disabling mirrored write operations in the cache system; testing the replacement memory module in the cache system; and restoring the mirrored data in the cache system. The restoring operation is accomplished by first quiescing write operations to stop writing data in the cache system not backed up in non-volatile data storage. Then data is copied from surviving memory modules to the replacement module, and the cooperative interaction of the surviving memory modules with the replacement memory module is validated. The validating operation verifies the cache modules are ready and the controllers are synchronized. After validation the quiesced write operations are un-quiesced, and mirrored-write operations for the cache system are enabled.

US Patent:

6601187, Jul 29, 2003

Filed:

Mar 31, 2000

Appl. No.:

09/539745

Inventors:

Stephen J. Sicola - Monument CO
Susan G. Elkington - Colorado Springs CO
Michael D. Walker - Colorado Springs CO
Paul Guttormson - Colorado Springs CO
Richard F. Lary - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L. P. - Houston TX

International Classification:

G06F 1100

US Classification:

714 6, 711162

Abstract:

A data replication system having a redundant configuration including dual Fibre Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. Each array controller in the system is capable of performing all of the data replication functions, and each host âseesâ remote data as if it were local. Each array controller has a dedicated link via a fabric to a partner on the remote side of the long-distance link between fabric elements. Each dedicated link does not appear to any host as an available link to them for data access; however, it is visible to the partner array controllers involved in data replication operations. These links are managed by each partner array controller as if being âclusteredâ with a reliable data link between them.

US Patent:

6618794, Sep 9, 2003

Filed:

Oct 31, 2000

Appl. No.:

09/702575

Inventors:

Stephen J. Sicola - Colorado Springs CO
James Pherson - Colorado Springs CO
Jesse Yandell - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1100

US Classification:

711154, 711114, 711161, 711162, 714 6, 714 15, 714 20, 707201, 707202, 707203, 707204

Abstract:

A system for generating a virtual point-in-time copy of a selected subset (e. g. , a selected volume or logical unit) of a storage system. The present system operates by using a bitmap in storage system controller cache memory to indicate blocks of memory in the selected volume that have been overwritten since the snapshot was initiated. When a write to the selected volume is requested, the cache bitmap is checked to determine whether the original data (in the area to be overwritten) has already been copied from the selected volume to a temporary volume. If the original data was previously copied, then the write proceeds to the selected volume. If, however, the original data would be overwritten by the presently requested write operation, then an area containing the original data is copied from the selected volume to a temporary volume. Reads from the temporary volume first check the bitmap to determine if the requested data has already been copied from the selected volume to the temporary volume. If so, the data is read from the temporary volume, otherwise, the data is read from the selected volume.

US Patent:

6629264, Sep 30, 2003

Filed:

Mar 30, 2000

Appl. No.:

09/538908

Inventors:

Stephen J. Sicola - Monument CO
Susan G. Elkington - Colorado Springs CO
Michael D. Walker - Colorado Springs CO
James E. Pherson - Colorado Springs CO
Roger L. Oakey - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1100

US Classification:

714 15, 714 18

Abstract:

A data replication system having a redundant configuration including dual Fiber Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The system employs the grouping of logical units into âassociation setsâ, for logging and failover purposes. The concept of association sets allows the system provides for proper ordering of I/O operations during logging across multiple volumes. In addition, association sets are employed by system to provide failure consistency by causing the group of logical units/volumes to all fail at the same time, ensuring a point in time consistency on the remote site.

US Patent:

6643795, Nov 4, 2003

Filed:

Mar 30, 2000

Appl. No.:

09/538680

Inventors:

Stephen J. Sicola - Monument CO
Susan G. Elkington - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1100

US Classification:

714 6, 714 7, 714 11, 714 13

Abstract:

A data replication system having a redundant configuration including dual Fiber Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The system includes the capability of simultaneous bi-directional remote data replication which permits the system to operate in an âextended clusterâ mode, as if each of the remote storage arrays were local relative to the respective remote host. The system further includes the concept of âhomeâ and âalternateâ storage nodes, which provide for automatic node failover from a primary to a designated alternate node, without necessitating re-booting of the remote node. Write data transfers are potentially host retry-able at both sites; upon failure of controllers at one site, the host re-issues the same write on other site.

US Patent:

6658540, Dec 2, 2003

Filed:

Mar 31, 2000

Appl. No.:

09/540309

Inventors:

Stephen J. Sicola - Monument CO
Susan G. Elkington - Colorado Springs CO
Michael D. Walker - Colorado Springs CO
Richard F. Lary - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1208

US Classification:

711162, 711161, 707204

Abstract:

A disaster-tolerant data backup and remote copy system which is implemented as a controller-based replication of one or more LUNs (logical units) between two remotely separated pairs of array controllers connected by redundant links. The system provides a method for allowing a large number of commands to be âoutstandingâ in transit between local and remote sites while ensuring the proper ordering of commands on remote media during asynchronous or synchronous data replication. In addition, the system provides a mechanism for automatic âtuningâ of links based on the distance between the array controllers.

US Patent:

6658590, Dec 2, 2003

Filed:

Mar 30, 2000

Appl. No.:

09/539011

Inventors:

Stephen J. Sicola - Monument CO
Susan G. Elkington - Colorado Springs CO
Michael D. Walker - Colorado Springs CO
James E. Pherson - Colorado Springs CO
Paul Guttormson - Colorado Springs CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 1100

US Classification:

714 6, 714 15, 714 20

Abstract:

A system which provides a completely redundant configuration including dual Fibre Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The array controllers perform a command and data logging function which stores all host write commands and data âmissedâ by the backup storage array during a situation wherein the links between the sites are down, the remote site is down, or where a site failover to the remote site has occurred. Log units are used to store, in order, all commands and data for every transaction which was âmissedâ by the backup storage array when one of the above system error conditions has occurred. The system provides rapid and accurate recovery of backup data at the remote site by sending all logged commands and data from the logging site over the link to the backup site in order, while avoiding the overhead of a full copy operation.