Wear leveling of a memory array

A method in a data storage system including a non-volatile memory array controlled by a controller, wherein the non-volatile memory array includes a plurality of subdivisions, the method comprising:

• the controller storing write data within the non-volatile memory array utilizing a plurality of block stripes, wherein at least some of the plurality of block stripes have differing numbers of blocks and all of the blocks within each block stripe are drawn from different ones of the plurality of subdivisions;
• the controller estimating remaining endurances of blocks in each of the plurality of subdivisions by reference to a plurality of endurance curves specified by a non-volatile memory operating model stored within the non-volatile memory array, wherein the determining includes:
• the controller selecting an endurance curve among the plurality of endurance curves based on a current value of a block health metric and current program/erase cycle count of a block;
• the controller determining the estimated remaining endurance of the block based on a subsequent program/erase cycle count at which the selected endurance curve reaches a threshold value of the block health metric, and
• the controller managing use of blocks in the plurality of subdivisions based on estimated remaining endurances of blocks in each of the plurality of subdivisions.

A program product, comprising:

• a storage device;
• and
• program code stored in the storage device, wherein the program code, when executed by a controller that controls a non-volatile memory array of a data storage system, causes the controller to perform:
• the controller storing write data within the non-volatile memory array utilizing a plurality of block stripes, wherein at least some of the plurality of block stripes have differing numbers of blocks of differing numbers of blocks and all of the blocks within each block stripe are drawn from different ones of the plurality of subdivisions;
• the controller determining a respective aggregate estimated remaining endurance across multiple blocks for each of the plurality of subdivisions based on both block health metrics and program/erase cycle counts of the blocks;
• and
• the controller building new block stripes for storing write data from blocks selected based on the aggregate estimated remaining endurances determined for the plurality of subdivisions, wherein the building includes:
• forming a new block stripe for write data of a given heat using blocks drawn from those of the plurality of subdivisions whose respective aggregate estimated remaining endurance satisfies a threshold and using no block from at least a particular subdivision for which the respective aggregate estimated remaining endurance does not satisfy the threshold, wherein blocks in the particular subdivision remain in active use for storing write data

A program product, comprising:

• a storage device;
• and
• program code stored in the storage device, wherein the program code, when executed by a controller that controls a non-volatile memory array of a data storage system, causes the controller to perform:
• the controller storing write data within the non-volatile memory array utilizing a plurality of block stripes, wherein at least some of the plurality of block stripes have differing numbers of blocks and all of the blocks within each block stripe are drawn from different ones of the plurality of subdivisions;
• the controller estimating remaining endurances of blocks in each of the plurality of subdivisions by reference to a plurality of endurance curves specified by a non-volatile memory operating model stored within the non-volatile memory array, and wherein the determining includes:
• the controller selecting an endurance curve among the plurality of endurance curves based on a current value of a block health metric and current program/erase cycle count of a block;
• the controller determining the estimated remaining endurance of the block based on a subsequent program/erase cycle count at which the selected endurance curve reaches a threshold value of the block health metric;
• and
• the controller managing use of blocks in the plurality of subdivisions based on estimated remaining endurances of blocks in each of the plurality of subdivisions.