Complex system and data transfer method

1. A storage system comprising;

one or more storage systems including a cache, a storage controller, and a storage device to store data;

wherein the storage device includes a storage box including a storage medium,

wherein the storage system is capable of performing a first write process in which data for a write request from the server is stored in the cache and then stored in the storage box, and a second write process in which data is stored in the storage box without being stored in the cache,

wherein the storage controller performs the first write process, based on the write request received from the server, the storage controller sets the address to store the data for the write request and notifies the storage box,

wherein the storage box:

receives write data from a server, and when redundant data from the write data received from the server can be generated by the storage box, generates the redundant data from the write data received from the server;

when the storage box can write the write data and the redundant data to the storage medium in accordance with an address received by the storage controller, writes the write data and the redundant data to the storage medium; and

transmits the write data to the storage controller when the storage box cannot generate the redundant data or cannot write the write data and the redundant data to the storage medium, and

wherein the storage controller stores the received write data in the cache.

2. The storage system according to claim 1 , wherein

when data that is not transmittable to the storage controller exists in the write data, the storage box notifies the storage controller of the existence of such data and an address of an area specified to write the data, and

the storage controller stores another copy of the write data into the address of the area of the cache specified to write the data.

3. The storage system according to claim 2 , wherein the storage controller abnormally ends a read request when the read request is received from the server for the stored area in the cache.

4. The storage system according to claim 1 ,

wherein the storage box transmits the write data to the storage controller when the storage box cannot generate the redundant data,

wherein the storage controller writes another copy of the write data received from the storage box to the cache.

5. The storage system according to claim 1 , wherein the storage box transmits the write data to the storage controller when the storage box cannot write the write data and the redundant data in an area specified from the server to be written in the storage medium.

6. The storage system according to claim 1 , wherein

the storage controller:

receives a write request specifying write areas from the server;

determines whether the specified write areas are sequential; and

instructs the storage box to receive write data from the server when the write areas are sequential.

7. The storage system according to claim 1 , wherein

the storage controller:

receives a write request specifying a write area from the server;

performs control such that data written by the write request is written in the storage medium with a log structure format; and

instructs the storage box to receive the data written by the write request.

8. The storage system according to claim 7 , wherein

the storage box calculates a hash value of the received write data, and transmits an identifier of the write data corresponding to the hash value to the storage controller, and

the storage controller stores the hash value and the corresponding identifier of the write data.

9. The storage system according to claim 8 , wherein

the storage box:

compares the received hash value with stored hash values; and

notifies the storage controller of a non-existence and the write data identifier when data having a hash value matching with the received hash value does not exist, and notifies the storage controller of the write data identifier and an address of an area storing data having a hash value matching with the received hash value when the data having the hash value matching with the received hash value does exist,

wherein the storage controller stores the write data and redundant data received from the storage box in the cache,

wherein if the read area data and the write data match, the storage box sends the information, the write data identifier, and the read area to the storage controller, and,

wherein the storage controller stores the store the identifier of the received write data and the read area.

10. The storage system according to claim 9 , wherein the storage controller:

sends a completion report to the server upon receipt of a report of receipt of the write data from the storage box; and

after the storage controller sends the completion report, the storage box generates the redundant data and writes the write data and redundant data to the storage medium.

11. A data transfer method in a complex system including: one or more storage systems including a cache, a storage controller, a storage device and a storage box including a storage medium,

wherein the storage device includes one or more storage boxes containing storage media,

wherein the storage system is capable of performing a first write process in which data for a write request from the server is stored in the cache and then stored in the storage box, and a second write process in which data is stored in the storage box without being stored in the cache,

when the storage controller performs the first write process, based on the write request received from the server, the storage controller sets the address to store the data for the write request and notifies the storage box,

wherein the storage box:

when redundant data can be generated from write data received from the server by the storage box, generates the redundant data from the write data received from the server;

when the storage box can write the write data and the redundant data to the storage medium, writes the write data and the redundant data to the storage medium in accordance with an address received by the storage controller; and

transmits the write data to the storage controller when the storage box cannot generate the redundant data or cannot write the write data and the redundant data to the storage medium, and

the storage controller stores the received write data in the cache.