Method of saving power consumed by a storage system

Abstract

Provided is a method of saving power consumed by a storage system that is connected to a host computer via a network, including a disk device for storing to be written data requested by the host computer, and controllers that control access to the disk device, in which the controllers each have an interface connected to the network, a processor connected to the interface, and a memory connected to the processor, in which the processor measures a load of the storage system, and in which the processor controls power to the controllers in accordance with the measured load of the storage system.

1 . A method of saving power consumed by a storage system that is connected to a host computer via a network, 
 wherein the storage system has a disk device for storing to be written data requested by the host computer, and plural controllers that control access to the disk device,    wherein the controllers each have an interface connected to the network, a processor connected to the interface, and a memory connected to the processor,    wherein the processor measures a load of the storage system, and    wherein the processor controls power to the controllers in accordance with the measured load of the storage system.    
   
   
       2 . The method of saving power consumed by a storage system according to  claim 1 , 
 wherein the memory stores controller count control information, which indicates the association between the load of the storage system and the count of operating controllers,    wherein, based on the controller count control information and the measured load of the storage system, the processor determines the number of controllers that are to be put into operation, and    wherein the processor controls power to the controllers in a manner that puts the determined number of controllers into operation.    
   
   
       3 . The method of saving power consumed by a storage system according to  claim 1 , 
 wherein the host computer recognizes a storage area of the disk device on a logical storage area basis, and    wherein, prior to turning off power to one of the controllers, the processor allocates a logical storage area allocated to this controller whose power is to be turned off to another controller.    
   
   
       4 . The method of saving power consumed by a storage system according to  claim 1 , 
 wherein the host computer recognizes a storage area of the disk device on a logical storage area basis, and    wherein, as the power is turned on in one of the controllers, the processor allocates a logical storage area allocated to another controller to the controller whose power is turned on.    
   
   
       5 . The method of saving power consumed by a storage system according to  claim 1 , wherein the processor controls power to the controllers in accordance with an instruction given from the host computer.  
   
   
       6 . The method of saving power consumed by a storage system according to  claim 1 , 
 wherein the memory stores mode management information, which indicates the association between the load of the storage system and an operation mode of the controllers, and    wherein, based on the measured load and the mode management information, the processor determines which operation mode is to be employed by the controllers.    
   
   
       7 . The method of saving power consumed by a storage system according to  claim 6 , wherein one operation mode differs from other operation modes in at least one of drive frequency of the processor, count of operating processors, and count of cores that are operating in each processor.  
   
   
       8 . A method of saving power consumed by a storage system that is connected to a host computer via a network, 
 wherein the storage system has a disk device for storing to be written data requested by the host computer, and plural controllers that controls access to the disk device,    wherein the controller has an interface connected to the network, a processor connected to the interface, and a memory connected to the processor,    wherein the memory stores mode management information, which indicates the association between a load of the storage system and an operation mode of the controller,    wherein the processor measures the load of the storage system, and wherein, based on the measured load and the mode management information, the processor determines which operation mode is to be employed by the controller.    
   
   
       9 . The method of saving power consumed by a storage system according to  claim 8 , wherein one operation mode differs from another operation mode in at least one of drive frequency of the processor, count of operating processors, and count of cores that are operating in each processor.  
   
   
       10 . The method of saving power consumed by a storage system according to  claim 8 , wherein the load of the storage system includes at least one of a activity ratio of the processor, a activity ratio of the interface, and a data transfer rate of the controller.  
   
   
       11 . The method of saving power consumed by a storage system according to  claim 8 , 
 wherein the storage system has plural controllers, and wherein the processor controls power to the controllers in accordance with the measured load of the storage system.    
   
   
       12 . A storage system accessed by a host computer, comprising: 
 a disk device to store to be written data requested by the host computer; and    plural controllers that control access to the disk device,    wherein the controllers each have: 
 a measuring unit which measures a load of the storage system; and  
 a power control unit which controls power to the controllers in accordance with the load of the storage system measured by the measuring unit.  
   
   
   
       13 . The storage system according to  claim 12 , 
 wherein the controllers stores controller count control information, which indicates the association between the load of the storage system and the count of operating controllers,    wherein, based on the controller count control information and the load of the storage system measured by the measuring unit, the power control unit determines the number of controllers that are to be put into operation, and    wherein the power control unit controls power to the controllers in a manner that puts the determined number of controllers into operation.    
   
   
       14 . The storage system according to  claim 12 , 
 wherein the host computer recognizes a storage area of the disk device on a logical storage area basis,    wherein each controller has an access control unit which controls allocation of the logical storage area, and    wherein, prior to shutting off power to one of the controllers, the access control unit allocates a logical storage area allocated to this controller whose power is to be turned off to another controller.    
   
   
       15 . The storage system according to  claim 12 , 
 wherein the host computer recognizes a storage area of the disk device on a logical storage area basis,    wherein each controller has an access control unit which controls allocation of the logical storage area, and    wherein, as the power is turned on in one of the controllers, the access control unit allocates a logical storage area allocated to another controller to the controller whose power is turned on.    
   
   
       16 . The storage system according to  claim 12 , wherein the power control unit controls power to the controllers in accordance with an instruction given by the host computer.  
   
   
       17 . The storage system according to  claim 12 , wherein the load of the storage system includes at least one of a activity ratio of the processor, a activity ratio of the interface, and a data transfer rate of the controllers.  
   
   
       18 . The storage system according to  claim 12 , 
 wherein the controllers store mode management information, which indicates the association between the load of the storage system and an operation mode of the controllers, and    wherein, based on the measured load and the mode management information, the power control unit determines which operation mode is to be employed by the controllers.    
   
   
       19 . The storage system according to  claim 18 , wherein one operation mode differs from other operation modes in at least one of drive frequency of the controller, count of operating controllers, and count of cores that are operating in each controller.