Memory system with memory region read counts and a memory group read count and operating method thereof

A method for operating a memory system, comprising:

• read-accessing a first memory region among a plurality of memory regions included in a memory region group;
• based on a first region read count corresponding to the first memory region among a plurality of region read counts respectively corresponding to the plurality of memory regions, increasing a group read count of the memory region group and reducing remaining region read counts other than the first region read count among the plurality of region read counts;
• and
• performing a reliability management operation for the memory region group, based on the group read count.

A memory system comprising:

• a memory device including at least a memory region group having first and second memory regions;
• and
• a controller configured to:
• increase a group read count for the memory region group by a preset amount while decreasing a second region read count for the second memory region by the preset amount when a first region read count for the first memory region reaches a first threshold due to a read-access to the first memory region;
• and
• control the memory device to move valid data of the memory region group into another memory region when the group read count reaches a second threshold.