RAID system, RAID controller and rebuilt/copy back processing method thereof
First Claim
1. A RAID system for accessing a connected disk device and executing an I/O request according to the I/O request requested by a host, comprising:
- a plurality of said disk devices constituting a RAID; and
a controller for executing an operation of reading data of a disk device, other than a failed disk device, when one of said plurality of disk devices failed, and writing the data to a spare disk device or a new disk device in parts for a plurality of times to execute Rebuild, or Copy back processing for reconstructing the RAID configuration,wherein said controller judges whether a normal I/O request, including an I/O request from said host, does not arrive for a predetermined time, concurrently executes read processing of one disk device and write processing of another disk device in said Rebuild or Copy back if said normal I/O request does not arrive for a predetermined time, andexecutes alternately said normal I/O request and a request of one of read and write of said disk device for one time of said Rebuild or Copy back if said normal I/O request arrives in a predetermined time.
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Accused Products
Abstract
A RAID system access a physical disk and perform Rebuild/Copy back processing according to a host I/O request, so as to implement high-speed Rebuild/Copy back processing without interfering with the processing of a normal I/O. When one disk device fails, out of a plurality of disk devices constituting a RAID configuration, the controller performs Rebuild/Copy back processing to reconstruct the RAID. In Rebuild/Copy back, the controller reads the data from one disk and writes the data to another disk, so the presence of a normal I/O is judged, and when a normal I/O is absent, read and write of these different disk drives are executed simultaneously. By this, the Rebuild/Copy back time can be decreased.
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Citations
17 Claims
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1. A RAID system for accessing a connected disk device and executing an I/O request according to the I/O request requested by a host, comprising:
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a plurality of said disk devices constituting a RAID; and a controller for executing an operation of reading data of a disk device, other than a failed disk device, when one of said plurality of disk devices failed, and writing the data to a spare disk device or a new disk device in parts for a plurality of times to execute Rebuild, or Copy back processing for reconstructing the RAID configuration, wherein said controller judges whether a normal I/O request, including an I/O request from said host, does not arrive for a predetermined time, concurrently executes read processing of one disk device and write processing of another disk device in said Rebuild or Copy back if said normal I/O request does not arrive for a predetermined time, and executes alternately said normal I/O request and a request of one of read and write of said disk device for one time of said Rebuild or Copy back if said normal I/O request arrives in a predetermined time. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A RAID controller for accessing a connected disk device and executing an I/O request according to the I/O request requested by a host, comprising:
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a first interface circuit for controlling interface with said host; a second interface circuit for controlling interface with said plurality of disk devices constituting the RAID; and a controller for executing an operation of reading data of a disk device, other than a failed disk device, when one of said plurality of disk devices fails, and writing the data to a spare disk device or a new disk device in parts for a plurality of times, and executing Rebuild or Copy back processing for reconstructing the RAID configuration, wherein said controller judges whether a normal I/O request, including an I/O request from said host, does not arrive for a predetermined time, concurrently executes read processing of one disk device and write processing of another disk device in said Rebuild or Copy back if said normal I/O request does not arrive for a predetermined time, and executes alternately said normal I/O request and a request of one of read and write of said disk device for one time of said Rebuild or Copy back if said normal I/O request arrives in a predetermined time. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A Rebuild/Copy back processing method for a RAID system which accesses a connected disk device and executes an I/O request according to the I/O request requested by a host, comprising the steps of:
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processing Rebuild/Copy back for executing an operation of reading data of a disk device, other than a failed disk device, when one of said plurality of disk devices constituting said RAID fails, and writing the data to a spare disk device or a new disk device in part for a plurality of times to execute Rebuild or Copy back processing for reconstructing the RAID configuration; judging whether a normal I/O request, including an I/O request from said host, does not arrive for a predetermined time; and concurrently executing read processing of one disk device and write processing of another disk device in said Rebuild or Copy back if said normal I/O request does not arrive for a predetermined time; and executing alternately said normal I/O request and a request of one of read and write of said disk device for one time of said Rebuild or Copy back if said normal I/O request arrives in a predetermined time. - View Dependent Claims (16, 17)
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Specification