In a memory system having multiple erase blocks in multiple planes, a selected number of erase blocks are programmed together as an adaptive metablock. The number of erase blocks in an adaptive metablock is chosen according to the data to be programmed. Logical address space is divided into logical groups, a logical group having the same size as one erase block. Adaptive logical blocks are formed from logical groups. One adaptive logical block is stored in one adaptive metablock.