Physical data layout to reduce seeks in a raid system
First Claim
1. A method of providing a storage space for a computer system, comprising the steps of:
- partitioning each of at least two physical data storage devices into primary and secondary storage spaces; and
defining a logical storage space within a storage controller connected to the physical data storage devices, wherein (i) a first portion of the logical storage space is defined to correspond to the primary storage space of a first one of the at least two physical data storage devices, and correspond to the secondary storage space of a second one of the at least two physical data storage devices, and (ii) a second portion of the logical storage space is defined to correspond to the primary storage space of the second physical data storage device, and correspond to the secondary storage space of the first physical data storage device.
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Accused Products
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.
11 Citations
24 Claims
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1. A method of providing a storage space for a computer system, comprising the steps of:
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partitioning each of at least two physical data storage devices into primary and secondary storage spaces; and
defining a logical storage space within a storage controller connected to the physical data storage devices, wherein (i) a first portion of the logical storage space is defined to correspond to the primary storage space of a first one of the at least two physical data storage devices, and correspond to the secondary storage space of a second one of the at least two physical data storage devices, and (ii) a second portion of the logical storage space is defined to correspond to the primary storage space of the second physical data storage device, and correspond to the secondary storage space of the first physical data storage device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for permanently storing information to be used by a computer system, comprising:
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a plurality of physical data storage devices; and
means, connected to said physical data storage devices, for defining a logical storage space wherein (i) a first portion of the logical storage space is defined to correspond to a primary storage space of a first one of the physical data storage devices, and correspond to a secondary storage space of a second one of the physical data storage devices, and (ii) a second portion 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. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 18, 19)
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17. A data storage system comprising:
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at least first and second hard disk drives, each including at least one rotating platter having a media-bearing surface thereon, any given one of the media-bearing surfaces having a plurality of concentric tracks, including inner and outer tracks;
a storage controller mapping a logical storage space onto the first and second hard disk drives, by defining a correspondence between a first portion of the logical storage space, a primary storage area overlying the outer tracks of the first hard disk drive, and a redundant secondary storage area overlying the inner tracks of the second hard disk drive, and by further defining a correspondence between a second portion of the logical storage space, another primary storage area overlying the outer tracks of the second hard disk drive, and another redundant secondary storage area overlying the inner tracks of the first hard disk drive; and
means for interfacing the storage controller with an external data processing system.
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20. A computer program product for a computer system having at least two physical data storage devices each of which is partitioned into primary and secondary storage spaces, comprising:
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a storage medium; and
program instructions for defining a logical storage space within a storage controller connected to the physical data storage devices, wherein (i) a first portion of the logical storage space is defined to correspond to the primary storage space of a first one of the at least two physical data storage devices, and correspond to the secondary storage space of a second one of the at least two physical data storage devices, and (ii) a second portion of the logical storage space is defined to correspond to the primary storage space of the second physical data storage device, and correspond to the secondary storage space of the first physical data storage device. - View Dependent Claims (21, 22, 23, 24)
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Specification