EP0426483A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Disk storage subsystem
Assignee: International Business Machines Corp
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Filing: 1990-11-01
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Granted: —
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Expires: 2010-11-01
Abstract
Abstract A data storage subsystem suitable for use in a data processing system is disclosed which comprises a number of separate physical housings (20,22,23,24), each housing having a number of disk supporting spindles (72) mounted therein. The velocity of rotation of the spindles within a housing is synchronized, and the rotational position of the spindles may be locked into a fixed relationship. When number N of disk supporting spindles are provided, spindle rotation is synchronized, and mirrored data files are written out of phase by 360/N degrees, thereby providing reduced latency time during a subsequent read operation, while at the same time providing data integrity through the use of redundant data files.
Inventors
- 👤 Thomas William Glaser
- 👤 Richard Greenberg
- 👤 Hjalmar Holmboe Ottesen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 15:35
CPC Classifications
G; G06; G06F; G06F11/00; G06F11/07; G06F11/16; G06F11/20; G06F11/2053; G06F11/2056; G06F11/2069; G11; G11B; G11B19/00; G11B19/02; G11B19/12; G11B19/20; G11B19/28; G11B27/00; G11B27/002; G11B27/10; G11C; G11C29/00; G11C29/70; G11C29/74; G11B2220/00; G11B2220/20; G11B2220/40; G11B2220/41; G11B2220/415
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
91 words
A method of writing mirror copies of a data file to a plurality of individual disk drives (70,71) in a disk storage subsystem, the method comprising the steps of: synchronising the positional rotation of the disks (73) in said disk drives, and writing mirror copies of said data file on the disks such that a data file on one disk in one disk drive is positionally staggered by a selected number of degrees of disk rotation with respect to the corresponding data file on a disk in a second disk drive.
Claim 2
Independent Claim
91 words
A method of writing mirror copies of a data file to a plurality of individual disk drives (70,71) in a disk storage subsystem, the method comprising the steps of: synchronising the positional rotation of the disks (73) in said disk drives, and writing mirror copies of said data file on the disks such that a data file on one disk in one disk drive is positionally staggered by a selected number of degrees of disk rotation with respect to the corresponding data file on a disk in a second disk drive.
Claim 3
Dependent Claim
54 words
A method as claimed in claim 1 including the steps of: providing an index signal for each revolution of the disks of one of said disk drives, and providing the index signal to all the other disk drives as a reference position by which the positional staggering of the data file may be determined.
Claim 4
Dependent Claim
39 words
A method as claimed in claim 1 or claim 2 wherein the disk drives are provided with a common velocity command signal, thereby causing the disks within all of the disk drives to rotate at substantially the same velocity.
Claim 5
Independent Claim
18 words
A method as claimed in any preceding claim wherein the disk drives are housed in a common housing.
Claim 6
Independent Claim
74 words
A method as claimed in any preceding claim further comprising the step of: subsequently reading the data file by using an individual write/read transducer means to access the disk of the one disk drive whose momentary rotational position is such that its copy of the data file will be next adjacent to the individual write/read transducer means for said disk drive means at the time of a need to read the mirrored data file.
Claim 7
Dependent Claim
325 words
A disk storage subsystem comprising: a plurality of disk drives (70,71); a master device (70) for the subsystem selected from one of an oscillator and a master drive which is one of said plurality of drives; one or more of the other disk drives being selectable as slave disk drives for the subsystem, each of said disk drives including a spindle (72) that supports at least one recording disk (73), motor means (74) for rotating the spindle, and motor servo means (85) for controlling said motor means, means to cause the spindles of all disk drives to rotate at substantially the same velocity, means providing an individual spindle velocity/position feedback signal for each of the disk drives, each of the individual spindle velocity/position feedback signals defining the rotational velocity and the rotational position of the spindle of each individual one of the disk drives, individual programmable delay signal means for at least some of said slave drives, each of said individual delay signal means defining an individual position of the spindle of a slave drive relative to the reference signal of said master device wherein said reference signal is one of an electronically generated signal and a spindle velocity/position feedbackk signal, and individual program enable means connected to said at least some of said slave drives, each of said individual program enable means having a first state wherein the reference signal from said master device and an individual one of said delay signal means operates to cause one of said at least some of said slave drives to be position synchronized to the reference signal of said master device, and each of said individual program enable means having a second state wherein the spindle velocity/position feedback signal of said one of said some of said slave drives operates to cause said one of said at least some of said slave drives to operate without being position synchronized to the reference signal of said master device.
Claim 8
Dependent Claim
325 words
A disk storage subsystem comprising: a plurality of disk drives (70,71); a master device (70) for the subsystem selected from one of an oscillator and a master drive which is one of said plurality of drives; one or more of the other disk drives being selectable as slave disk drives for the subsystem, each of said disk drives including a spindle (72) that supports at least one recording disk (73), motor means (74) for rotating the spindle, and motor servo means (85) for controlling said motor means, means to cause the spindles of all disk drives to rotate at substantially the same velocity, means providing an individual spindle velocity/position feedback signal for each of the disk drives, each of the individual spindle velocity/position feedback signals defining the rotational velocity and the rotational position of the spindle of each individual one of the disk drives, individual programmable delay signal means for at least some of said slave drives, each of said individual delay signal means defining an individual position of the spindle of a slave drive relative to the reference signal of said master device wherein said reference signal is one of an electronically generated signal and a spindle velocity/position feedbackk signal, and individual program enable means connected to said at least some of said slave drives, each of said individual program enable means having a first state wherein the reference signal from said master device and an individual one of said delay signal means operates to cause one of said at least some of said slave drives to be position synchronized to the reference signal of said master device, and each of said individual program enable means having a second state wherein the spindle velocity/position feedback signal of said one of said some of said slave drives operates to cause said one of said at least some of said slave drives to operate without being position synchronized to the reference signal of said master device.
Claim 9
Dependent Claim
89 words
The disk storage subsystem as claimed in claim 6 wherein said means acting to cause the spindles to rotate at substantially the same velocity comprises a common spindle velocity command signal, connected to the disk drive motor servo means, which provides a reference time period in which the related spindle should experience a predetermined portion of one revolution, and wherein each of said individual spindle velocity/position feedback signals provides a measure of the time period that it took the related spindle to rotate said predetermined portion of one revolution.
Claim 10
Dependent Claim
50 words
A disk storage subsystem as claimed in claim 6 or claim 7, wherein each of said individual spindle velocity/position feedback signals comprises time separated signal pulses, two time adjacent pulses of which indicate the time period that it took the related spindle to rotate said predetermined portion of one revolution.
Claim 11
Dependent Claim
22 words
A disk storage subsystem as claimed in claim 7 or claim 8, wherein said predetermined portion of one revolution comprises 360 degrees.
Claim 12
Dependent Claim
175 words
A disk storage subsystem as claimed in any of claims 6 to 9 wherein said individual program enable means connected to said at least some of said slave drives comprises, a plurality of first AND gate means, one for each of said at least some of said slave drives, each of said first AND gate means being enabled by an individual one of said program enable means when in said first state, and each of said first AND gate means receiving as an input an individual one of said individual programmable delay signal means, and the reference signal of said master device, and a plurality of second AND gate means, one for each of said at least some of said slave drives, each of said second AND gate means being enabled by an individual one of said program enable means when in said second state, and each of said second AND gate means receiving as an input the spindle velocity/position feedback signal of the related one of said at least some of said slave drives.
Claim 13
Dependent Claim
121 words
A disk storage subsystem as claimed in claim 10 wherein when said first AND gate means is enabled the spindle of the related one of said at least some of said slave drives is velocity controlled to be of the same velocity as dictated by said master device, and to be in a predetermined position relationship to the spindle of said master drive, said predetermined position being determined by said individual programmable delay signal means,and when said second AND gate means is enabled the spindle of the related one of said at least some of said slave drives is velocity controlled to be of the same velocity as dictated by said master device, without a predetermined relative position relationship between drives.
Claim 14
Independent Claim
249 words
A method of providing a disk drive subsystem having a plurality of individual disk drives, one disk drive of which comprises the master drive of said subsystem, and the other disk drives of which may be selectively slaved to operate with a predetermined disk position relative to the disk position of said master drive, comprising the steps of, providing a common disk velocity command signal for each of said disk drives, to thereby cause the disks of all disk drives to rotate at substantially the same velocity, providing individually selectable disk position signals for at least some of said slave drives, each of said individual disk position signals defining a position of the disk of the related slave drive relative to the position of the disk of said master drive, and providing an individual enabling means for each of said at least some of said slave drives, each of said individual enabling means having a first enabling state wherein the disk velocity/position feedback signal from said master drive and an individual one of said disk position signals operates to cause the related one of said slave drives to be position synchronized to the position of the disk of said master drive, and each of said individual enabling means having a second disabling state wherein the velocity/position feedback signal of the related slave drive operates to cause the related slave drive disk to rotate without a position that is synchronized to the position of the disk of said master drive.
Claim 15
Independent Claim
249 words
A method of providing a disk drive subsystem having a plurality of individual disk drives, one disk drive of which comprises the master drive of said subsystem, and the other disk drives of which may be selectively slaved to operate with a predetermined disk position relative to the disk position of said master drive, comprising the steps of, providing a common disk velocity command signal for each of said disk drives, to thereby cause the disks of all disk drives to rotate at substantially the same velocity, providing individually selectable disk position signals for at least some of said slave drives, each of said individual disk position signals defining a position of the disk of the related slave drive relative to the position of the disk of said master drive, and providing an individual enabling means for each of said at least some of said slave drives, each of said individual enabling means having a first enabling state wherein the disk velocity/position feedback signal from said master drive and an individual one of said disk position signals operates to cause the related one of said slave drives to be position synchronized to the position of the disk of said master drive, and each of said individual enabling means having a second disabling state wherein the velocity/position feedback signal of the related slave drive operates to cause the related slave drive disk to rotate without a position that is synchronized to the position of the disk of said master drive.
Claim 16
Dependent Claim
67 words
A method as claimed in claim 12 including the step of providing said common disk velocity command signal as a reference time period in which the related disk should experience a predetermined portion of one revolution, and providing said individual disk velocity/position feedback signals as a signal that measures the time period that it actually took the related disk to rotate said predetermined portion of one revolution.
Claim 17
Dependent Claim
21 words
A method as claimed in claim 13 wherein said predetermined portion of one revolution comprises 360 degrees of a disk revolution.
Claim 18
Independent Claim
63 words
A method as claimed in any of claims 12 to 14 wherein said plurality individual disk drives equals the number N, including the steps of, providing mirrored data files within each of said N disk drives, and positionally staggering the similar data that is stored in said mirrored data files of each of said N disk drives by 360/N degrees of disk rotation.
Claim 19
Dependent Claim
63 words
A method as claimed in claim 15 wherein said step of providing an individual velocity/feedback signal for each of said disk drives includings the steps of, providing an index position signal during each revolution of a disk of said master drive, and providing said index position signal to said slave drives as a reference position by which said positional staggering may be controlled.
Claim 20
Dependent Claim
21 words
A method as claimed in claim 15 or claim 16, wherein said N disk drives are housed in a common housing.
References Cited (Backward Citations)
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