Controller, storage apparatus, and computer program product
First Claim
1. A controller that controls writing into a first data-storage unit and a second data-storage unit included in a storage apparatus, and reading from the first data-storage unit and the second data-storage unit, the second data-storage unit storing user data of which writing is requested by a host device and parity data of the user data, the first data-storage unit storing the parity data, a storage area in the second data-storage unit in which user data is stored having a first state and a second state, the first state being a state that user data stored in the storage area is protected by the parity data stored by the first data-storage unit, the second state being a state that user data stored in the storage area is not protected by the parity data stored by the first data-storage unit, the controller comprising:
- a parity updating unit that updates the parity data when the state of the storage area is changed, and writes first parity data into the first data-storage unit, the first parity data being the updated parity data; and
a parity writing unit that reads the parity data written in the first data-storage unit and writes second parity data into the second data-storage unit at a timing determined independently from the timing of updating of the parity data, the second parity data being the read parity data.
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Accused Products
Abstract
According to one embodiment, a controller controls writing into and reading from a storage apparatus that includes a first data-storage unit and a second data-storage unit. The second data-storage unit stores user data and parity data of the user data. The first data-storage unit stores the parity data. The controller includes a parity updating unit and a parity writing unit. When parity data is updated, the parity updating unit writes the updated parity data into the first data-storage unit. When a certain requirement is satisfied, the parity writing unit reads the parity data written in the first data-storage unit, and writes the parity data thus read into the second data-storage unit.
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Citations
9 Claims
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1. A controller that controls writing into a first data-storage unit and a second data-storage unit included in a storage apparatus, and reading from the first data-storage unit and the second data-storage unit, the second data-storage unit storing user data of which writing is requested by a host device and parity data of the user data, the first data-storage unit storing the parity data, a storage area in the second data-storage unit in which user data is stored having a first state and a second state, the first state being a state that user data stored in the storage area is protected by the parity data stored by the first data-storage unit, the second state being a state that user data stored in the storage area is not protected by the parity data stored by the first data-storage unit, the controller comprising:
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a parity updating unit that updates the parity data when the state of the storage area is changed, and writes first parity data into the first data-storage unit, the first parity data being the updated parity data; and a parity writing unit that reads the parity data written in the first data-storage unit and writes second parity data into the second data-storage unit at a timing determined independently from the timing of updating of the parity data, the second parity data being the read parity data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A storage apparatus comprising:
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a first data-storage unit that stores parity data of user data of which writing is requested by a host device; a second data-storage unit that stores the user data and the parity data; and a controller that controls writing into the first data-storage unit and the second data-storage unit, and reading from the first data-storage unit and the second data-storage unit, a storage area in the second data-storage unit in which user data is stored having a first state and a second state, the first state being a state that user data stored in the storage area is protected by the parity data stored by the first data-storage unit, the second state being a state that user data stored in the storage area is not protected by the parity data stored by the first data-storage unit, wherein the controller comprises a parity updating unit that updates the parity data when state of the storage area is changed, and writes first parity data into the first data-storage unit, the first parity data being the updated parity data, and a parity writing unit that reads the parity data written in the first data-storage unit and writes second parity data into the second data-storage unit at a timing determined independently from the timing of updating of the parity data, the second parity data being the read parity data.
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9. A computer program product having a non-transitory computer readable medium including programmed instructions, wherein when executed by a computer that controls writing into and reading from a first data-storage unit and a second data-storage unit included in a storage apparatus, the first data-storage unit storing parity data of user data of which writing is requested by a host device, and the second data-storage unit storing the user data and the parity data, a storage area in the second data-storage unit in which user data is stored having a first state and a second state, the first state being a state that user data stored in the storage area is protected by the parity data stored by the first data-storage unit, the second state being a state that user data stored in the storage area is not protected by the parity data stored by the first data-storage unit the instructions cause the computer to function as:
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a parity updating unit that updates the parity data when state of the storage area is changed, and writes first parity data into the first data-storage unit, the first parity data being the updated parity data; and a parity writing unit that reads the parity data written in the first data-storage unit and writes second parity data into the second data-storage unit at a timing determined independently from the timing of updating of the parity data, the second parity data being the read parity data.
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Specification