Data migration method

Abstract

Data migration arrangements for storage systems are disclosed.

1 . A system comprising: 
 a first storage system having a first port and a first storage area assigned to a first identifier which is a kind of an i-SCSI name;    a second storage system having a second port;    a computer;    a network, configured to adapt to an i-SCSI protocol, coupling the first storage system, the second storage system and the computer; and    a name management computer coupled to the first storage system, the second storage system and the computer via the network,    wherein    the computer establishes a first communication path from the computer itself to the first port of the first storage system for accessing from the computer to the first storage area via the first port by using the first identifier;    after creation of the first communication path, the first storage system designates the second storage system to create a second storage area to be assigned to the first identifier which is already assigned to the first storage area in the first storage system,    the second storage system creates the second storage area assigned to the first identifier based on the designation of the first storage system,    the second storage system sends information of the second port and the second storage area together with information of the first identifier to the name management computer after the creation of the second storage area assigned the first identifier,    the name management computer notifies the computer that the second storage area is assigned to the first identifier based on the information of the second port and the second storage area sent from the second storage system,    the computer establishes a second communication path from the computer itself to the second port of the second storage system after the second storage area assigned the first identifier has been created in the second storage system and in response to the notification from the name management computer,    the computer disconnects the first communication path after establishment of the second communication path and then conducts communication with the second storage system by using the second communication path and the first identifier so that the computer can access the second storage area in the second storage system instead of the, first storage area by using the first identifier which is not changed.    
   
   
       2 . The system according to  claim 1 , wherein, before the creation of the second storage area assigned the first identifier is designated to the second storage system by the first storage system, the first storage system sends data stored in the first storage area in the first storage system to a third storage area in the second storage system via the network, 
 wherein, when the creation of the second storage area assigned the first identifier is designated by the first storage system, the second storage system creates the second storage area assigned the first identifier by assigning the first identifier to the third storage area where the data are stored.    
   
   
       3 . The system according to  claim 2 , wherein the first storage system requests the name management computer to delete information of association of the first storage area and the first identifier after the second storage area has been created in the second storage system, 
 the name management computer notifies the computer of the deletion information of association of the first storage area and the first identifier in response to the request from the first storage system, and    the computer disconnects the first communication path in response to the notification of the deletion from the name management computer.    
   
   
       4 . The system according to  claim 3 , when the second communication path is created, the second storage system sends a command, which requests the computer not to use the second communication path until the first communication path is disconnected, to the computer via the second communication path.  
   
   
       5 . The system according to  claim 4 , wherein the name management computer communicates with the first storage system, the second storage system and the computer by using iSNSP.  
   
   
       6 . A data migration method in a system comprising a first storage device, a second storage device, a computer and a name management device, the first storage device including a first physical port, a first logical volume and a target to which the first physical port and the first logical volume are allocated and the target having a first identifier of iSCSI name, the second storage device including a second physical port, the computer which establishes a first communication path from the computer to the first physical port and accesses to the target by using the first communication path and the first identifier, the name management device which stores association information of the first identifier of the target and a first network address of the first physical port and the first storage device, the second storage device, the computer and the name management device being coupled by an i-SCSI network, the method comprising: 
 a step in which the first storage device copies data stored in the first logical volume to a second logical volume in the second storage device;    a step in which after completion of the copying, the first storage device designates the second storage device to assign the target, having the first identifier which is already allocated to the first physical port and the first logical volume, to the second logical volume and the second physical port;    a step in which the second storage device allocates the second logical volume and the second physical port to the target;    a step in which the second storage device notifies the name management device that the second physical port and the second logical volume are allocated to the target;    a step in which the name management device adds a relationship between the target and a second network address of the second physical port to the association information and notifies the computer that the second physical port and the second logical volume are added to the target and the second network address of the second physical port;    a step in which the computer receives the notification of addition from the name management device and establishes a second communication path from the computer itself to the second physical port by using the second network address of the second physical port;    a step in which said first storage device notifies the name management device that the first physical port is deleted from the target;    a step in which the name management device deletes a relationship between the target and the first network address of the first physical port from the association information and notifies the computer that the first physical port has been deleted from the target; and    a step in which the computer receives the notification of deletion from the name management device, disconnects the first communication path, and maintains an access to the target by using the second communication path.    
   
   
       7 . The data migration method according to  claim 6 , further comprising: 
 a step in which, when the second communication path is created, the second storage device sends a command, which requests the computer not to use the second communication path until the first communication path is disconnected, to the computer via the second communication path.    
   
   
       8 . A system comprising: 
 a first storage device including a first physical port and a first logical volume which are allocated to a target, the target being assigned to a first identifier of an i-SCSI name;    a second storage device including a second physical port;    a computer coupled to the first storage device and the second storage device; and    a name management device coupled to the first storage device, the second storage device, and the computer via a network, wherein the computer establishes a first communication path from the computer to the first physical port and conducts access to the target by using the first communication path and the first identifier;    the first storage device replicates data stored in the first logical volume to a second logical volume in the second storage device;    after completion of said replication, the first storage device designates the second storage device to create the target having the first identifier assigned to the target in the first storage device;    the second storage device allocates the second logical volume and the second physical port to the target after receiving the designation from the first storage device;    the second storage device notifies the name management device that the second physical port and the second logical volume are allocated to the target;    the name management device notifies the computer that the second physical port and the second logical volume are added to the target;    the computer receives the notification of addition from the name management device and establishes a second communication path from the computer to the second physical port;    the first storage device notifies the name management device that the first physical port and the first logical volume are deleted from the target;    the name management device notifies the computer that the first physical port and the first logical volume are deleted from the target; and    the computer receives the notification of deletion from the name management device, disconnects the first communication path, and maintains the access to the target by using the second communication path and the first identifier which is not changed.    
   
   
       9 . The system according to  claim 8 , when the second communication path is created, the second storage device sends command, which request the computer not to use the second communication path until the first communication path is disconnected, to the computer via the second communication path.