Switching device, switch control method, and storage system

A switch control method comprising:

• acquiring command queuing numbers in a plurality of storage devices that make up a virtual disk, each of the command queuing numbers indicating an upper limit of a number of process-waiting instructions that can be stored in the corresponding storage device;
• selecting a minimum value in the command queuing numbers acquired from the storage devices;
• setting the selected minimum value as a command queuing number indicating an upper limit of a number of process-waiting instructions which is stored in the virtual disk;
• shifting data from one virtual disk to another virtual disk among virtual disks;
• informing, when the shift of data is performed, a computation device that is connected thereto of status modification of the virtual disk that stores the data;
• receiving a setting request of a command queuing number of the virtual disk to which the data is shifted from the computation device that receives the status modification;
• acquiring a command queuing number of each of the storage devices that make up the virtual disk to which the data is shifted when the request is received;
• selecting a minimum value of the command queuing numbers acquired from the storage devices that make up the virtual disk to which the data is shifted;
• and
• setting the selected minimum value as the command queuing number of the virtual disk to which the data is shifted.

A storage system comprising a computation device;

• a switching device;
• and a plurality of storage devices, wherein
• the computation device includes a command output unit that outputs instructions for reading and writing data from and into the storage devices to the switching device,
• the switching device includes
• a queue number acquiring unit that acquires command queuing numbers in a plurality of storage devices that make up a virtual disk, each of the command queuing numbers indicating an upper limit of a number of process-waiting instructions that can be stored in the corresponding storage device;
• a selecting unit that selects a minimum value in the command queuing numbers acquired from the storage devices;
• a queue number setting unit that sets the selected minimum value as a command queuing number indicating an upper limit of a number of process-waiting instructions which is stored in the virtual disk;
• a data shifting unit that shifts data from one virtual disk to another virtual disk among virtual disks;
• and
• a modification informing unit that informs, when the shift of data is performed, the computation device of status modification of the virtual disk that stores the data, wherein
• when a setting request of a command queuing number of the virtual disk to which the data is shifted is received from the computation device that receives the status modification,
• the queue number acquiring unit acquires a command queuing number of each of the storage devices that make up the virtual disk to which the data is shifted,
• the selecting unit selects a minimum value in the command queuing numbers acquired from the storage devices that make up the virtual disk to which the data is shifted, and
• the queue number setting unit sets the selected minimum value as the command queuing number of the virtual disk to which the data is shifted,
• the storage device includes
• an instruction storing unit that stores therein the input instructions;
• and
• a process executing unit that sequentially processes the stored instructions, and
• the command output unit outputs the instructions by using the set command queuing number as the upper limit of the number of the process-waiting instructions of each virtual disk.

A storage system comprising:

• a command output unit that outputs instructions for reading and writing data from and into a plurality of storage devices,
• a queue number acquiring unit that acquires command queuing numbers in the storage devices that make up a virtual disk, each of the command queuing numbers indicating an upper limit of a number of process-waiting instructions that can be stored in the corresponding storage device;
• a selecting unit that selects a minimum value in the command queuing numbers acquired from the storage devices;
• a queue number setting unit that sets the selected minimum value as a command queuing number indicating an upper limit of a number of process-waiting instructions which is stored in the virtual disk;
• a data shifting unit that shifts data from one virtual disk to another virtual disk among virtual disks;
• a modification informing unit that informs, when the shift of data is performed, the computation device of status modification of the virtual disk that stores the data;
• an instruction storing unit that stores therein the input instructions;
• and
• a process executing unit that sequentially processes the stored instructions, wherein
• when a setting request of a command queuing number of the virtual disk to which the data is shifted is received from the computation device that receives the status modification,
• the queue number acquiring unit acquires a command queuing number of each of the storage devices that make up the virtual disk to which the data is shifted,
• the selecting unit selects a minimum value in the command queuing numbers acquired from the storage devices that make up the virtual disk to which the data is shifted, and
• the queue number setting unit sets the selected minimum value as the command queuing number of the virtual disk to which the data is shifted, and
• the command output unit outputs the instructions by using the set command queuing number as the upper limit of the number of the process-waiting instructions of each virtual disk.