Memory system and control method

An integrated memory system comprising a plurality of memory systems, each of the memory systems connectable to a host and comprising:

• a nonvolatile memory including a memory region;
• an interface configured to receive mirroring information from the host, the mirroring information indicating:
• i) a number of mirroring regions assigned by the host for performing a mirroring operation to redundantly store data in the memory region of the plurality of memory systems;
• and ii) an identifier of a mirroring region assigned to the memory region of its own memory system;
• and
• a controller configured to:
• maintain patrol cycle information indicating a patrol cycle with respect to an identifier of each of mirroring regions for each of different numbers of mirroring regions;
• upon receiving the mirroring information from the host via the host interface, set a patrol cycle for the memory region of its own memory system with reference to a part of the patrol cycle information corresponding to the number of mirroring regions and the identifier indicated by the mirroring information from the host;
• and
• perform a patrol process with respect to the memory region of its own memory system at the set patrol cycle, the patrol process comprising reading of data from the memory region of its own memory system and then writing of the read data into another memory region of its own memory system after error correction included in the read data.

A method of controlling a memory system including a nonvolatile memory having a first memory region, and a host interface connectable to a host, the method comprising:

• maintaining patrol cycle information indicating a patrol cycle with respect to an identifier of each of mirroring regions for each of different numbers of mirroring regions;
• receiving, from the host via the host interface, mirroring information indicating:
• i) a number of mirroring regions assigned by the host for performing a mirroring operation to redundantly store data at least in the first memory region and a second memory region that is within or out of the memory system;
• and ii) an identifier of a mirroring region assigned to the first memory region;
• upon receiving the mirroring information from the host via the host interface, setting a patrol cycle for the first memory region with reference to a part of the patrol cycle information corresponding to the number of mirroring regions and the identifier indicated by the mirroring information from the host;
• and
• performing a patrol process with respect to the first memory region at the set patrol cycle, the patrol process comprising reading of data from the first memory region and then writing of the read data into another memory region after error correction included in the read data.