According to one embodiment, a memory system includes a nonvolatile memory, and a controller electrically connected to the nonvolatile memory. The controller receives, from a host, a write command including a logical block address. The controller obtains a total amount of data written to the nonvolatile memory by the host during a time ranging from a last write to the logical block address to a current write to the logical block address, or time data associated with a time elapsing from the last write to the logical block address to the current write to the logical block address. The controller notifies the host of the total amount of data or the time data as a response to the received write command.