Magnetic disk device and method for saving management information
AssigneeKabushiki Kaisha Toshiba
InventorsSatoru Adachi, Masaaki Motoki, Mitsuaki Sudou
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Abstract
According to one embodiment, a controller in a magnetic disk device saves a write data sequence including a plurality of write data blocks not written to a disk, and first management information, for the plurality of write data blocks, from which logical block addresses are excluded, in a nonvolatile memory in response to a decrease in a voltage of a power supply for the magnetic disk device. The plurality of write data blocks are added with redundancy codes respectively. Logical block addresses of the plurality of write data blocks are embedded in the redundancy codes respectively.
Claims20
A magnetic disk device comprising:
- a first volatile memory;
- a nonvolatile memory;
- and
- a controller configured to save a write data sequence including a plurality of write data blocks not written to a disk, and first management information, for the plurality of write data blocks, from which logical block addresses are excluded, in the nonvolatile memory in response to a decrease in a voltage of a power supply for the magnetic disk device, the plurality of write data blocks being externally transferred and stored in the first volatile memory and added with redundancy codes respectively, the redundancy codes being associated with the plurality of write data blocks respectively, and logical block addresses of the plurality of write data blocks being embedded in the redundancy codes respectively.
A method, in a magnetic disk device comprising a first volatile memory and a nonvolatile memory, for saving management information, the method comprising:
- saving a write data sequence including a plurality of write data blocks not written to a disk, in the nonvolatile memory in response to a decrease in a voltage of a power supply for the magnetic disk device, the plurality of write data blocks being externally transferred and stored in the first volatile memory and added with redundancy codes respectively, the redundancy codes being associated with the plurality of write data blocks respectively, and logical block addresses of the plurality of write data blocks being embedded in the redundancy codes respectively;
- and
- saving first management information, for the plurality of write data blocks, from which logical block addresses are excluded, in the nonvolatile memory in response to a decrease in the voltage of the power supply for the magnetic disk device.
Dependencies are inferred from the claim text.