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公开(公告)号：DE602004019534D1
公开(公告)日：2009-04-02
申请号：DE602004019534
申请日：2004-07-07
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT , SMITH DANIEL FELIX
Abstract: The error tolerance of an array of m storage units is increased by using a technique referred to as dodging. A plurality of k stripes are stored across the array of storage units in which each stripe has n+r elements that correspond to a symmetric code having a minimum Hamming distance d=r+1. Each respective element of a stripe is stored on a different storage unit. An element is selected when a difference between a minimum distance of the donor stripe and a minimum distance of a recipient stripe is greater or equal to 2. The selected element is also stored on a storage unit having no elements of the recipient stripe. A lost element of the recipient stripe is then rebuilt on the selected element.
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公开(公告)号：IN190181B
公开(公告)日：2003-06-28
申请号：IN363DE1995
申请日：1995-03-06
Applicant: IBM
Inventor： BEST JOHN STEWART , CHIANG WEN-WEI , HETZLER STEVEN ROBERT , HORNE DONALD EDWARD , LEE CHIH-KUNG , MARRELLO VINCENT
IPC: G06K19/00
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公开(公告)号：DE69617110T2
公开(公告)日：2002-08-01
申请号：DE69617110
申请日：1996-06-27
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT
Abstract: The present invention provides a data recording disk drive for use in a portable, battery-powered computer having several power-save modes of operation. The power-save modes are entered after a computed time since the last data read or write command. The computed time to enter a power-save mode is based on the computer user's real-time workload and is thus continuously varying during operation of the disk drive. The disk drive detects the current user workload by calculating the frequency of disk drive accesses and based on this history determines which of a plurality of power-save modes is appropriate and when to enter a power-save mode. Each disk drive read or write access is detected and used to compute a current access frequency. The current access frequency is compared to a previously calculated and continuously updated threshold frequency. The threshold frequency is representative of the access pattern, e.g., uniform or sporadic, and is computed from equations that include adjustable gain factors. The appropriate power-save mode is entered when the current access frequency falls below the threshold frequency. Intermediate power-save modes can be skipped, based on the detected access pattern. The disk drive can also adapt dynamically to varying workload situations, thereby saving more energy without degrading performance. This is accomplished by adjusting the gain factors in response to tracking the actual performance of the system, thereby changing the threshold frequency. The disk drive also determines when to exit a power-save mode without necessarily waiting for a user access. The power-save modes can also be customized for different disk drive products without the need to conform to some standard for setting fixed times, or number of power-save modes. New user-selectable parameters, such as on/off, performance, and energy targets can be used to replace fixed mode-entry times. These parameters adjust the gain factors and thus the threshold frequency. This alters the equations used to determine when to enter a power-save mode.
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公开(公告)号：DE69617110D1
公开(公告)日：2002-01-03
申请号：DE69617110
申请日：1996-06-27
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT
Abstract: The present invention provides a data recording disk drive for use in a portable, battery-powered computer having several power-save modes of operation. The power-save modes are entered after a computed time since the last data read or write command. The computed time to enter a power-save mode is based on the computer user's real-time workload and is thus continuously varying during operation of the disk drive. The disk drive detects the current user workload by calculating the frequency of disk drive accesses and based on this history determines which of a plurality of power-save modes is appropriate and when to enter a power-save mode. Each disk drive read or write access is detected and used to compute a current access frequency. The current access frequency is compared to a previously calculated and continuously updated threshold frequency. The threshold frequency is representative of the access pattern, e.g., uniform or sporadic, and is computed from equations that include adjustable gain factors. The appropriate power-save mode is entered when the current access frequency falls below the threshold frequency. Intermediate power-save modes can be skipped, based on the detected access pattern. The disk drive can also adapt dynamically to varying workload situations, thereby saving more energy without degrading performance. This is accomplished by adjusting the gain factors in response to tracking the actual performance of the system, thereby changing the threshold frequency. The disk drive also determines when to exit a power-save mode without necessarily waiting for a user access. The power-save modes can also be customized for different disk drive products without the need to conform to some standard for setting fixed times, or number of power-save modes. New user-selectable parameters, such as on/off, performance, and energy targets can be used to replace fixed mode-entry times. These parameters adjust the gain factors and thus the threshold frequency. This alters the equations used to determine when to enter a power-save mode.
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公开(公告)号：ES2157241T3
公开(公告)日：2001-08-16
申请号：ES94309305
申请日：1994-12-13
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT , KABELAC WILLIAM JOHN
IPC: G11B5/55 , G11B5/56 , G11B5/596 , G11B19/12 , G11B20/10 , G11B20/12 , G11B20/18 , G11B21/08 , G11B21/10 , G11B27/30
Abstract: A sector servo, zone bit recording disk drive includes a sector architecture in which the recording head locates and identifies data sectors without using data ID fields, but instead using information obtained from electronic storage and from servo sectors which need not be adjacent to the data sectors. The tracks contain servo information and data, but not data sector ID information. The tracks in each zone are circumferentially divided into segments. Included in each segment is a number of data regions separated from one another by servo sectors. The data regions may contain partial data sectors and complete data sectors. The format information provided to identify and locate data sectors, including ones whose region locations are not adjacent to servo sectors, includes an entry for each region in the section. Each entry includes the lengths of the first and last data sections in the region, whether the sectors represented by those sections are split between two regions, the total number of data sectors in the region, and the sector number of the first data sector in the region. The information provided in the servo sectors consists of a servo sector number or other indicia which enables the disk drive to determine the position of the recording head and begin reading or writing immediately upon settling on-track and without incurring a latency penalty.
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Patent Agency Ranking
公开(公告)号：DE69427273D1
公开(公告)日：2001-06-28
申请号：DE69427273
申请日：1994-12-13
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT , KABELAC WILLIAM JOHN
IPC: G11B5/55 , G11B5/56 , G11B5/596 , G11B19/12 , G11B20/10 , G11B20/12 , G11B20/18 , G11B21/08 , G11B21/10 , G11B27/30
Abstract: A sector servo, zone bit recording disk drive includes a sector architecture in which the recording head locates and identifies data sectors without using data ID fields, but instead using information obtained from electronic storage and from servo sectors which need not be adjacent to the data sectors. The tracks contain servo information and data, but not data sector ID information. The tracks in each zone are circumferentially divided into segments. Included in each segment is a number of data regions separated from one another by servo sectors. The data regions may contain partial data sectors and complete data sectors. The format information provided to identify and locate data sectors, including ones whose region locations are not adjacent to servo sectors, includes an entry for each region in the section. Each entry includes the lengths of the first and last data sections in the region, whether the sectors represented by those sections are split between two regions, the total number of data sectors in the region, and the sector number of the first data sector in the region. The information provided in the servo sectors consists of a servo sector number or other indicia which enables the disk drive to determine the position of the recording head and begin reading or writing immediately upon settling on-track and without incurring a latency penalty.
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公开(公告)号：DE69131142T2
公开(公告)日：1999-11-18
申请号：DE69131142
申请日：1991-01-17
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT
Abstract: A method and means is described wherein servo sectors written on a disk (or servo sections written on a tape) are equally spaced on a given track and read during seek, settle and track following operations. An algorithm is used to determine the allowable time separation between servo sectors (or sections) on a track and lengths of associated data sections, such as data sectors or variable length records, that may be accommodated on the disk or tape in such manner that each of the servo sectors (or sections) equally spaced on a given track is located within a data field of a data sector or within an identification region or immediately after an address indicating mark (such as address marker index mark). The rate at which the servo sector (or section) is sampled is constant and independent of the number and lengths of the data sections. As a result of this independent relationship, this technique is suitable for CLD recording, to banded disks using sectored servo as in conventional FBA, and also even to non-sectored architectures, such as count-key-data (CKD), wherein the data is written in records of variable length, and to tape drives formatted in FBA or CKD.
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公开(公告)号：DE69229200D1
公开(公告)日：1999-06-24
申请号：DE69229200
申请日：1992-06-25
Applicant: IBM
Inventor： BEST JOHN STEWART , HETZLER STEVEN ROBERT
Abstract: A data recording disk file is provided with a fixed block architecture sector format that eliminates the ID region. The servo region contains sector identification information in the form of a start-of-track indicating mark recorded in a selected sector of each track and a start-of-sector indicating mark recorded in each sector. A full track number identifier is encoded in the position field within the servo region of each sector. A look-up table is built at format time to map bad sectors out of the disk file. The table contains entries for each cluster of contiguous bad sectors, and is searched at runtime to provide conversion of logical sector location identifiers to physical sector location identifiers.
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公开(公告)号：DE69505524D1
公开(公告)日：1998-11-26
申请号：DE69505524
申请日：1995-05-18
Applicant: IBM
Inventor： BEST JOHN STEWART , CHIANG WEN-WEI , HETZLER STEVEN ROBERT , HORNE DONALD EDWARD , LEE CHIH-KUNG , MARRELLO VINCENT
Abstract: A non-invasive servo-write system for use in a data recording disk drive. The system measures actuator position and generates a reference clock using semiconductor lasers. Internal position references are provided by reflective diffraction gratings affixed to the actuator arm and the spindle hub. Wavefront reconstruction optics correct for aberrations in the gratings. Optical sensors detect differential changes in the diffraction patterns created by the gratings, eliminating sensitivity to frequency drift. Decode electronics convert optical sensor data into an actuator position measurement. Control electronics drive the voice coil motor within the disk drive, which positions the write transducer to record servo information provided in a servo pattern generator. Transparent windows in the head-disk-assembly cover allow the servo-writer to write drives which are completely assembled and sealed.
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公开(公告)号：SG46190A1
公开(公告)日：1998-02-20
申请号：SG1996000406
申请日：1994-12-13
Applicant: IBM
Inventor： HETZLER STEVEN ROBERT , KABELAC WILLIAM JOHN
IPC: G11B5/55 , G11B5/56 , G11B5/596 , G11B19/12 , G11B20/10 , G11B20/12 , G11B20/18 , G11B21/08 , G11B21/10 , G11B27/30
Abstract: A sector servo, zone bit recording disk drive includes a sector architecture in which the recording head locates and identifies data sectors without using data ID fields, but instead using information obtained from electronic storage and from servo sectors which need not be adjacent to the data sectors. The tracks contain servo information and data, but not data sector ID information. The tracks in each zone are circumferentially divided into segments. Included in each segment is a number of data regions separated from one another by servo sectors. The data regions may contain partial data sectors and complete data sectors. The format information provided to identify and locate data sectors, including ones whose region locations are not adjacent to servo sectors, includes an entry for each region in the section. Each entry includes the lengths of the first and last data sections in the region, whether the sectors represented by those sections are split between two regions, the total number of data sectors in the region, and the sector number of the first data sector in the region. The information provided in the servo sectors consists of a servo sector number or other indicia which enables the disk drive to determine the position of the recording head and begin reading or writing immediately upon settling on-track and without incurring a latency penalty.
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