Storage system and data transfer method
A storage system includes at least one drive chassis connected to at least one host computer via a first network, and a storage controller connected to the drive chassis, in which the storage controller instructs the drive chassis to create a logical volume, and the drive chassis creates a logical volume according to an instruction from the storage controller, provides a storage area of the storage system to the host computer, and receives an IO command from the host computer to the storage area of the storage system.
1. A storage system comprising:
at least one drive chassis having a storage unit; and
a storage controller coupled to the at least one drive chassis,
wherein the at least one drive chassis is configured to:
create a logical volume having according to an instruction from the storage controller and provide the logical volume to a host computer as a storage area;
receive a first write command issued from the host computer to the logical volume; and
transmit a second write command corresponding to the first write command to the storage controller,
wherein the storage controller is configured to:
transmit a reply of the second write command to the at least one drive chassis, and
wherein the at least one drive chassis is further configured to:
create a redundant data of write data and store the redundant data into the storage unit, after receipt of the reply of the second write command; and
perform a redundancy operation to reduce the amount of the redundant data stored in the storage unit.
2. The storage system according to claim 1 , wherein the at least one drive chassis is further configured to:
have a plurality of drives as the storage unit.
3. The storage system according to claim 2 , wherein the redundancy operation is performed using parity data.
4. The storage system according to claim 2 , wherein the at least one drive chassis is further configured to:
perform a reply of the first write command to the host computer after the first redundancy operation and before the second redundancy operation.
5. The storage system according to claim 2 , wherein the at least one drive chassis is further configured to:
perform a reply of the first write command to the host computer, after storing the write data in the storage area, or, after performing the second redundancy operation.
6. A data transfer method of a storage system including at least one drive chassis having a storage unit and a storage controller coupled to the at least one drive chassis, the method comprising:
executing a first process for the at least one drive chassis, the first process comprising:
creating a logical volume having according to an instruction from the storage controller and provide the logical volume to a host computer as a storage area;
receiving a first write command issued from the host computer to the logical volume; and
transmitting a second write command corresponding to the first write command to the storage controller; and
executing a second process for the storage controller, the second process comprising:
transmitting a reply of the second write command to the at least one drive chassis,
wherein the first process is further configured to:
have a plurality of drives as the storage unit;
create a redundant data of write data and store into the plurality of drives, after receipt of the reply of the second write command; and
perform a redundancy operation to reduce the amount of the redundant data stored in the plurality of drives.