Abstract: A volume to which a storage function is applied is migrated without copying data written to a volume as a migration object between computers while maintaining functionality of the storage function. A plurality of computers are accessibly connected to each of one or more physical storage devices. Each computer migrates ownership of the volume as the migration object to a computer as a destination. When the migration object volume from a first computer to a second computer is an owner volume to which a storage function is applied, the storage function requiring control data for I/O of data, the control data being metadata other than domain mapping data (indicating a relationship between a volume region and a storage region and being metadata for the owner volume), in place of or in addition to the domain mapping data.

Abstract: A volume to which a storage function is applied is migrated without copying data written to a volume as a migration object between computers while maintaining functionality of the storage function. A plurality of computers are accessibly connected to each of one or more physical storage devices. Each computer migrates ownership of the volume as the migration object to a computer as a destination. When the migration object volume from a first computer to a second computer is an owner volume to which a storage function is applied, the storage function requiring control data for I/O of data, the control data being metadata other than domain mapping data (indicating a relationship between a volume region and a storage region and being metadata for the owner volume), in place of or in addition to the domain mapping data.

Abstract: A distributed storage system includes an edge system including edge nodes, and a core system, which is coupled to the edge system via a network, and is configured to hold backup data of the edge system. Each of the edge nodes is configured to provide a volume to a host, generate XOR update differential data representing a differential between a first generation snapshot of the volume and an old generation snapshot of the volume, the old generation being older than the first generation, and transmit the generated XOR update differential data to the core system. The core system is configured to hold, as the backup data, erasure codes generated based on pieces of XOR update differential data transmitted from the edge nodes, and update the erasure codes based on the pieces of XOR update differential data received from the edge nodes.

Abstract: The storage system is capable of creating one or more virtual storage subsystems to which virtual resources having logically divided a processing capacity of the physical resources are allocated, and upon creating a virtual volume for receiving I/O requests from the host within the virtual storage subsystem, the virtual storage subsystem allocates the virtual resource to the virtual volume, and when an I/O request to the virtual volume is received from the host, performs processing related to the I/O request using the virtual resource having been allocated. According further to the storage system, after allocating the virtual resource to the virtual volume, the storage system raises a utilization rate of the virtual resource allocated to the virtual volume in a stepwise manner.

Abstract: A distributed storage system includes an edge system including edge nodes, and a core system, which is coupled to the edge system via a network, and is configured to hold backup data of the edge system. Each of the edge nodes is configured to provide a volume to a host, generate XOR update differential data representing a differential between a first generation snapshot of the volume and an old generation snapshot of the volume, the old generation being older than the first generation, and transmit the generated XOR update differential data to the core system. The core system is configured to hold, as the backup data, erasure codes generated based on pieces of XOR update differential data transmitted from the edge nodes, and update the erasure codes based on the pieces of XOR update differential data received from the edge nodes.

Abstract: A processor receives a command from a server computer to designate a plurality of addresses related to a plurality of logical storage areas, and write a plurality of write data to the logical storage areas. The processor receives the write data and writes it to storage areas different from storage areas in which a plurality of holding data are stored in a first memory. When the processor determines that the write data are written to the first memory, the processor transmits a success response to a host computer. When the write data satisfy a predetermined condition, the processor writes the write data in the first memory to a plurality of first device storage areas. When it is determined that at least a part of the data is not written to the first memory, the processor transmits a failure response to the host computer.

Abstract: The storage system is capable of creating one or more virtual storage subsystems to which virtual resources having logically divided a processing capacity of the physical resources are allocated, and upon creating a virtual volume for receiving I/O requests from the host within the virtual storage subsystem, the virtual storage subsystem allocates the virtual resource to the virtual volume, and when an I/O request to the virtual volume is received from the host, performs processing related to the I/O request using the virtual resource having been allocated. According further to the storage system, after allocating the virtual resource to the virtual volume, the storage system raises a utilization rate of the virtual resource allocated to the virtual volume in a stepwise manner.

Abstract: In executing a balancing process for moving data between a plurality of storage device groups constituted by a plurality of storage devices, a storage system determines whether or not to execute a balancing process for satisfying a first avoidance requirement for avoiding the occurrence of a problem in any one storage device only, on the basis of a second avoidance requirement which is satisfied by a second balancing process executed prior to a first balancing process for satisfying the first avoidance requirement, and executes the first balancing process in a case where the result of this determination is affirmative.

Abstract: A processor receives a command from a server computer to designate a plurality of addresses related to a plurality of logical storage areas, and write a plurality of write data to the logical storage areas. The processor receives the write data and writes it to storage areas different from storage areas in which a plurality of holding data are stored in a first memory. When the processor determines that the write data are written to the first memory, the processor transmits a success response to a host computer. When the write data satisfy a predetermined condition, the processor writes the write data in the first memory to a plurality of first device storage areas. When it is determined that at least a part of the data is not written to the first memory, the processor transmits a failure response to the host computer.

Abstract: In executing a balancing process for moving data between a plurality of storage device groups constituted by a plurality of storage devices, a storage system determines whether or not to execute a balancing process for satisfying a first avoidance requirement for avoiding the occurrence of a problem in any one storage device only, on the basis of a second avoidance requirement which is satisfied by a second balancing process executed prior to a first balancing process for satisfying the first avoidance requirement, and executes the first balancing process in a case where the result of this determination is affirmative.