Distributed storage system, distributed storage system control method, and storage medium

A control method for a distributed storage system, the distributed storage system including a plurality of nodes coupled to each other, the plurality of nodes each including a processor, a memory, a storage device, and a network interface,

• the control method comprising:
• managing, by each of the plurality of nodes, physical chunks obtained by dividing a physical storage area of the storage device by a predetermined size;
• a logical chunk management step of managing, by the each of the plurality of nodes, as each of logical chunks, a logical storage area to which one or more physical chunks among the physical chunks is allocated;
• a volume management step of providing, by the each of the plurality of nodes, a volume to which one or more logical chunks among the logical chunks is allocated, to outside;
• and
• a pair management step of managing, by the each of the plurality of nodes, as a pair, the logical chunks storing the same data among the plurality of nodes,
• the volume management step comprising identifying, when a write request for the data is received, one of the logical chunks that forms a designated volume, and transmitting an instruction to write the data to the identified one of the logical chunks,
• the logical chunk management step comprising receiving the instruction to write the data to the one of the logical chunks, identifying one of the physical chunks that forms the one of the logical chunks, and transmitting an instruction to write the data to the one of the physical chunks,
• the managing of the physical chunks comprising receiving the instruction to write the data to the one of the physical chunks, and writing the data to the identified one of the physical chunks,
• the pair management step comprising calculating a hash value of the data, transmitting the hash value to another node, and issuing a query about presence or absence of the same hash value.

A non-transitory computer-readable storage medium having stored thereon a program for controlling each of nodes that includes a processor, a memory, a storage device, and a network interface, to execute:

• managing physical chunks obtained by dividing a physical storage area of the storage device by a predetermined size;
• a logical chunk management step of managing as each of logical chunks, a logical storage area to which one or more physical chunks among the physical chunks is allocated;
• a volume management step of providing a volume to which one or more logical chunks among the logical chunks is allocated, to outside;
• and
• a pair management step of managing, as a pair, the logical chunks storing the same data among the nodes,
• the volume management step comprising identifying, when a write request for the data is received, one of the logical chunks that forms a designated volume, and transmitting an instruction to write the data to the identified one of the logical chunks,
• the logical chunk management step comprising receiving the instruction to write the data to the one of the logical chunks, identifying one of the physical chunks that forms the one of the logical chunks, and transmitting an instruction to write the data to the one of the physical chunks,
• the managing of the physical chunks comprising receiving the instruction to write the data to the one of the physical chunks, and writing the data to the identified one of the physical chunks,
• the pair management step comprising calculating a hash value of the data, transmitting the hash value to another node, and issuing a query about presence or absence of the same hash value.