A storage array includes a first controller, memory, and one or more storage devices. Each of the storage devices comprises a second controller and a nonvolatile memory. The first controller receives a command and data from a host connected to the storage array and transmits a response or data to the host. When a write command, write data, and size information of the write data are received from the host, the first controller sends the received data to the second controller. The second controller determines a write address indicating a memory region of the nonvolatile memory in which the write data are to be written, based on the write command and the size information, writes the write data in the memory region associated with the write address, and transmits the write address to the first controller. The first controller further transfers the write address to the host.