Memory controller and storage device which selects memory devices in which data is to be written based on evaluation values of a usable capacity of the memory devices

1. A memory controller comprising:

a memory which stores first data, that manages a write amount with respect to each of a plurality of regions where a plurality of nonvolatile memories are classified by a predetermined size, and second data that manages a write state corresponding to the plurality of nonvolatile memories;

an adjustment part which, in writing of data to be written in the plurality of nonvolatile memories, calculates a first evaluation value to each of the plurality of nonvolatile memories, based on the first data and the second data stored in the memory and selects the nonvolatile memory in which the data to be written is to be written, based on the first evaluation value;

a write part which writes the data to be written in the nonvolatile memory selected by the adjustment part and updates the first data and the second data stored in the memory; and

a setting change part which calculates a second evaluation value to each of the plurality of nonvolatile memories, based on the first data and the second data stored in the memory after starting to use the plurality of nonvolatile memories and changes setting of a usable capacity with respect to at least one of the plurality of nonvolatile memories, based on the second evaluation value.

2. The memory controller of claim 1 , wherein the adjustment part further calculates, when data to be rearranged that are written in the plurality of nonvolatile memories are rearranged in the plurality of nonvolatile memories, a third evaluation value to each of the plurality of nonvolatile memories, based on the first data and the second data,

selects the nonvolatile memory in which the data to be rearranged is to be rearranged, based on the third evaluation value,

writes the data to be rearranged in the nonvolatile memory in which the data is to be rearranged, and

updates the first data and the second data stored in the memory.

3. The memory controller of claim 1 , wherein the first data includes first statistical information to the plurality of regions,

the second data includes second statistical information to the plurality of nonvolatile memories, and

the adjustment part selects the nonvolatile memory in which the data is to be written such that at least one of a performance evaluation value and an endurance evaluation value to each of the plurality of nonvolatile memories is equalized among the plurality of nonvolatile memories and changes setting of the usable capacity to at least one of the plurality of nonvolatile memories.

4. The memory controller of claim 1 , further comprising a change part which changes a value of a parameter used in calculation executed by the adjustment part.

5. A storage device comprising:

a plurality of nonvolatile memory devices in which setting of a usable capacity is changeable after starting to use;

a memory which stores first data, that manages a write amount with respect to each of a plurality of regions where storage regions of the plurality of nonvolatile memory devices are classified by a predetermined size, and second data that manages a write state corresponding to the plurality of nonvolatile memory devices;

an adjustment part which, in writing of data to be written in the plurality of nonvolatile memory devices, calculates a first evaluation value to each of the plurality of nonvolatile memory devices, based on the first data and the second data stored in the memory and selects the nonvolatile memory device in which the data to be written is to be written, based on the first evaluation value;

a write part which writes the data to be written in the nonvolatile memory device selected by the adjustment part and updates the first data and the second data stored in the memory; and

a setting change part which calculates a second evaluation value to each of the plurality of nonvolatile memory devices, based on the first data and the second data stored in the memory after starting to use the plurality of nonvolatile memory devices and changes setting of the usable capacity with respect to at least one of the plurality of nonvolatile memory devices, based on the second evaluation value.

6. The storage device of claim 5 , wherein the plurality of nonvolatile memory devices are a plurality of disk arrays, and

each of the plurality of disk arrays includes a plurality of solid state drives.

7. A control method of controlling a storage device comprising a plurality of nonvolatile memory devices in which setting of a usable capacity is changeable after starting to use, the method comprising:

storing, in a memory, first data, that manages a write amount with respect to each of a plurality of regions where storage regions of the plurality of nonvolatile memory devices are classified by a predetermined size, and second data that manages a write state corresponding to the plurality of nonvolatile memory devices;

calculating, in writing of data to be written in the plurality of nonvolatile memory devices, a first evaluation value to each of the plurality of nonvolatile memory devices, based on the first data and the second data stored in the memory and selecting the nonvolatile memory device in which the data to be written is to be written, based on the first evaluation value;

writing the data to be written in the selected nonvolatile memory device and updating the first data and the second data stored in the memory; and

calculating a second evaluation value to each of the plurality of nonvolatile memory devices, based on the first data and the second data stored in the memory after starting to use the plurality of nonvolatile memory devices and changing setting of the usable capacity with respect to at least one of the plurality of nonvolatile memory devices, based on the second evaluation value.