Joe E Smothers

US Patent:

6681290, Jan 20, 2004

Filed:

Jan 29, 2001

Appl. No.:

09/772265

Inventors:

Carl Evan Jones - Tucson AZ
Joe Edward Smothers - Tucson AZ

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1200

US Classification:

711114, 707204, 713 1, 713 2, 713100

Abstract:

A data storage subsystem which reduces seek time, by defining a logical storage space wherein part of the logical storage space is defined to correspond to a primary storage space of a first physical data storage device, and correspond to a secondary storage space of a second physical data storage device, and another part of the logical storage space is defined to correspond to a primary storage space of the second physical data storage device, and correspond to a secondary storage space of the first physical data storage device. For hard disk drives having an arm assembly with a read/write head, the average seek distance for both drives reduced, since the pivoting arm assembly need not travel as far to reach each physical storage address within a primary storage area. The invention may additionally take advantage of geometric or other aspects of the storage devices which result in some portion of the device having a faster access time that another portion. For hard disk drives which assign a larger number of logical blocks to the outer tracks of the disk than to the inner tracks, the storage controller can map the primary storage space of a given one of the drives to the outer tracks of the drive.

US Patent:

6345295, Feb 5, 2002

Filed:

Jan 22, 1999

Appl. No.:

09/235303

Inventors:

Brent Cameron Beardsley - Tucson AZ
Carl Evan Jones - Tucson AZ
William Griswold Sherman - Tucson AZ
Joe Edward Smothers - Tucson AZ

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 1338

US Classification:

709224, 709223, 709106, 709227, 714 38, 714 45, 714 35, 717 4

Abstract:

A trace facility for a computer system attachment network, a method for operating that network, and trace tools in the network. The network has a plurality of the trace tools, each connected to a communication path, the trace facility providing a system wide trace. The trace facility comprises at least one trace buffer at each trace tool. Each trace tool has an address filter selecting an address range of information on the bus, the information being communicated on the bus as events, and storing the selected event information in the trace buffers, thereby conducting a trace. A breakpoint connection is provided interconnecting each of the trace tools. A trace tool control at each trace tool responds to a trace stop command addressed to the trace tool, to stop the trace at its address filter and trace buffer, and to issue a breakpoint signal on the breakpoint connection to all the interconnected trace tools. The interconnected trace tools respond to the breakpoint signal to stop the trace thereat, so that the trace is saved at each trace tool. An elapse clock provides a time stamp for each traced event to allow determination of the timing of each event.