A host system configured to communicate with a storage system, including a host flash translation layer (FTL) configured to manage a plurality of blocks included in the storage system, wherein the host FTL includes a block assignment module configured to generate priority information indicating priorities of free blocks from among the plurality of blocks based on erase count values of the free blocks, and wherein the host FTL is configured to assign a free block having a lowest erase count value, from among the free blocks, for a data write operation based on the priority information; a counting circuit configured to count a number of erase operations performed on each of the plurality of blocks; and an interface circuit configured to transmit to the storage system a block address along with an access request to the storage system, the block address indicating a position of the assigned free block.