Memory system and method of controlling nonvolatile memory

A memory system connectable to a host, comprising:

• a nonvolatile memory including a plurality of nonvolatile memory dies each including a plurality of physical blocks;
• and
• a controller electrically connected to the nonvolatile memory and configured to control a plurality of block groups each including a plurality of physical blocks selected from the nonvolatile memory dies, wherein
• the controller is configured to:
• in response to receiving a write request from the host, the write request specifying a first identifier of identifying first write data to be written and length of the first write data, allocate a block group from the block groups as a first write destination block group, and write the first write data into each non-defective physical block belonging to the first write destination block group, in units of first data sizes, such that writing to a defective physical block belonging to the first write destination block group is skipped;
• and
• notify the host of first information including:
• the first identifier;
• an address specifying the first write destination block group;
• a first offset indicating a top write destination physical storage location in the first write destination block group in which the first write data is written;
• the length of the first write data;
• and first bitmap information including a plurality of bits, each of the plurality of bits corresponding to each of the physical blocks belonging to the first write destination block group, each of the plurality of bits having a value indicating whether or not the corresponding physical block is a defective block.