Storage system comprising flash memory modules subject to two wear—leveling processes

A storage system comprising:

• a plurality of flash memory modules, each of the plurality of flash memory modules including one or more flash memory chips and a memory controller which is configured to manage a plurality of blocks with the one or more flash memory chips, each of the plurality of blocks is a unit for erasing data stored in the one or more flash memory chips;
• and
• a storage controller configured to manage a logical volume and control data transfer from/to the plurality of flash memory modules in response to read/write request to the logical volume, and
• perform wear leveling by exchanging data between at least one first flash memory module and at least one second flash memory module included in the plurality of flash memory modules for leveling data erase count among the plurality flash memory modules.

A storage system comprising:

• a plurality of flash memory modules, each of the plurality of flash memory modules including one or more flash memory chips and a memory controller which is configured to manage a plurality of blocks with the one or more flash memory chips, each of the plurality of blocks is a unit for erasing data stored in the one or more flash memory chips;
• and
• a storage controller configured to manage a plurality of virtual storage areas corresponding to a plurality of logical storage areas provided by the plurality of flash memory modules and control data transfer from/to the plurality of flash memory modules in response to read/write request to the plurality of virtual storage areas, and
• perform wear leveling by exchanging data stored in the plurality of logical storage areas between at least one first flash memory module and at least one second flash memory module included in the plurality of flash memory modules.

A storage system comprising:

• a plurality of flash memory modules, each of the plurality of flash memory modules including one or more flash memory chips and a memory controller which is configured to manage a plurality of blocks with the one or more flash memory chips, each of the plurality of blocks is a unit for erasing data stored in the one or more flash memory chips;
• and
• a storage controller being configured to:
• manage a plurality of RAID groups, each of the plurality of RAID groups including a set of flash memory modules in the plurality of flash memory modules, and
• perform wear leveling by exchanging data between at least one first flash memory module and at least one second flash memory module included in the plurality of flash memory modules.