Disk array system, disk controller, and method for performing rebuild process
First Claim
1. A disk array system for distributing and storing data on a plurality of disk units and for accessing the plurality of disk units in response to an I/O request from a host, the system comprising:
- the plurality of disk units which stores distributed and redundant data;
a spare disk unit which functions in place of part of the plurality of disk units in which a failure has occurred; and
a disk controller including;
a rebuild process section which restores data stored on a faulty disk unit by the use of data stored on disk units other than the faulty disk unit by management unit areas obtained by dividing a storage area of each disk unit by predetermined management units, and writes the data onto the spare disk unit;
a management information storage section which stores rebuild management information including information which indicates whether a rebuild process is completed in each management unit area; and
a rebuild control section which accepts the I/O request from the host, specifies a management unit area including a target area of the I/O request in the case of the target area of the I/O request being included in a target area of the rebuild process, rebuilds data in the management unit area by the rebuild process section in the case of the determination that the rebuild process is not yet completed in the management unit area specified being made on the basis of the rebuild management information, and permits the I/O request after rebuilding the data.
1 Assignment
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Accused Products
Abstract
In a disk array system, when a failure occurs in a disk unit under control, a disk controller performs a rebuild process for rebuilding data stored on the faulty disk unit on a spare disk unit (HS). When a rebuild control section accepts an I/O request from a host before completing the rebuild process in all target areas, the rebuild control section specifies a management unit area including a target area of the I/O request and determines whether the rebuild process is completed in the management unit area. If the rebuild process is not completed in the management unit area, the rebuild control section performs the rebuild process in the management unit area by a rebuild process section and rebuilds data on the HS. After that, an I/O request handling section handles the I/O request.
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Citations
8 Claims
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1. A disk array system for distributing and storing data on a plurality of disk units and for accessing the plurality of disk units in response to an I/O request from a host, the system comprising:
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the plurality of disk units which stores distributed and redundant data; a spare disk unit which functions in place of part of the plurality of disk units in which a failure has occurred; and a disk controller including; a rebuild process section which restores data stored on a faulty disk unit by the use of data stored on disk units other than the faulty disk unit by management unit areas obtained by dividing a storage area of each disk unit by predetermined management units, and writes the data onto the spare disk unit; a management information storage section which stores rebuild management information including information which indicates whether a rebuild process is completed in each management unit area; and a rebuild control section which accepts the I/O request from the host, specifies a management unit area including a target area of the I/O request in the case of the target area of the I/O request being included in a target area of the rebuild process, rebuilds data in the management unit area by the rebuild process section in the case of the determination that the rebuild process is not yet completed in the management unit area specified being made on the basis of the rebuild management information, and permits the I/O request after rebuilding the data. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A disk controller for distributing and storing data on a plurality of disk units and for accessing the plurality of disk units in response to an I/O request from a host, the disk controller comprising:
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a rebuild process section which restores data stored on a faulty disk unit by the use of data stored on disk units other than the faulty disk unit by management unit areas obtained by dividing a storage area of each of the plurality of disk units for storing distributed data and redundant data by predetermined management units, and writes the restored data onto a spare disk unit which functions in place of the faulty disk unit; a management information storage section which stores rebuild management information including information which indicates whether a rebuild process is completed in each management unit area; and a rebuild control section which accepts the I/O request from the host, for specifying a management unit area including a target area of the I/O request in the case of the target area of the I/O request being included in a target area of the rebuild process, rebuilds data in the management unit area by the rebuild process section in the case of the determination that the rebuild process is not yet completed in the management unit area specified being made on the basis of the rebuild management information, and permits the I/O request after rebuilding the data.
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8. A method for performing a rebuild process by a disk array system for distributing and storing data on a plurality of disk units and for accessing the plurality of disk units in response to an I/O request from a host, the method comprising:
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restoring data stored on a faulty disk unit by the use of data stored on disk units other than the faulty disk unit by management unit areas obtained by dividing a storage area of each of the plurality of disk units for storing distributed data and redundant data by predetermined management units, and writing the restored data onto a spare disk unit which functions in place of the faulty disk unit by a rebuild process section; accepting the I/O request from the host, specifying a management unit area including a target area of the I/O request in the case of the target area of the I/O request being included in a target area of the rebuild process, reading out rebuild management information including information which indicates whether the rebuild process is completed in each management unit area from a management information storage section, and determining by a rebuild control section on the basis of the rebuild management information whether the rebuild process is not yet completed in the management unit area specified; rebuilding data in the management unit area by the rebuild process section in the case of the determination that the rebuild process is not yet completed in the management unit area; and permitting the I/O request, by the rebuild control section, after rebuilding the data by the rebuild process section.
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Specification