Storage system having function to backup data in cache memory
First Claim
1. A storage system, comprising:
- a plurality of control modules for receiving I/O commands sent from a host device;
a plurality of storage devices for storing data according to I/O commands from the host device; and
a non-volatile storage resource which serves as the plurality of storage devices or another kind of non-volatile storage device, whereineach control module comprises a cache memory and a control unit, and the control unit writes data according to an I/O command from the host device to the cache memory, and writes the data written in the cache memory to at least one of the plurality of storage devices or sends the data to the host device,a first control unit in a first control module, out of the plurality of control modules, instructs a second control unit in a second control module out of the plurality of control modules to copy one or more dirty data elements out of a plurality of dirty data elements, which are stored in a first cache memory in the first control module and have not yet been written in the storage device,the second control unit writes the one or more dirty data elements to a second cache memory in the second control module in response to the copy instruction, and backs up the one or more dirty data elements from the second cache memory to the non-volatile storage resource, andthe first control unit backs up dirty data elements, other than the one or more dirty data elements of which copying has completed from among the plurality of dirty data elements, from the first cache memory to the non-volatile storage resource.
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Accused Products
Abstract
A storage system comprises a plurality of control modules having a plurality of cache memories respectively. One or more dirty data elements out of a plurality of dirty data elements stored in a first cache memory in a first control module are copied to a second cache memory in a second control module. The one or more dirty data elements stored in the second cache memory are backed up to a non-volatile storage resource. The dirty data elements backed up from the first cache memory to the non-volatile storage resource are dirty data elements other than the one or more dirty data elements of which copying has completed, out of the plurality of dirty data elements.
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Citations
20 Claims
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1. A storage system, comprising:
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a plurality of control modules for receiving I/O commands sent from a host device; a plurality of storage devices for storing data according to I/O commands from the host device; and a non-volatile storage resource which serves as the plurality of storage devices or another kind of non-volatile storage device, wherein each control module comprises a cache memory and a control unit, and the control unit writes data according to an I/O command from the host device to the cache memory, and writes the data written in the cache memory to at least one of the plurality of storage devices or sends the data to the host device, a first control unit in a first control module, out of the plurality of control modules, instructs a second control unit in a second control module out of the plurality of control modules to copy one or more dirty data elements out of a plurality of dirty data elements, which are stored in a first cache memory in the first control module and have not yet been written in the storage device, the second control unit writes the one or more dirty data elements to a second cache memory in the second control module in response to the copy instruction, and backs up the one or more dirty data elements from the second cache memory to the non-volatile storage resource, and the first control unit backs up dirty data elements, other than the one or more dirty data elements of which copying has completed from among the plurality of dirty data elements, from the first cache memory to the non-volatile storage resource. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for backing up data stored in a cache memory, which is performed in a storage system for temporarily storing data from a host device to a cache memory and then writing the data to a storage device,
the method comprising steps of: -
copying one or more dirty data elements out of a plurality of dirty data elements, which have not yet been written in the storage device and are stored in a first cache memory in a first control module out of a plurality of control modules having a plurality of cache memories respectively, to a second cache memory in a second control module out of the plurality of control modules; backing up the one or more dirty data elements from the second cache memory to a non-volatile storage resource, which is a storage device or another kind of non-volatile storage device; and backing up the dirty data elements other than the one or more dirty data elements of which copying has completed out of the plurality of dirty data elements from the first cache memory to the non-volatile storage resource. - View Dependent Claims (17, 18, 19, 20)
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Specification