Storage system and operation method of storage system

Abstract

The present invention is able to improve the processing performance of a storage system by respectively virtualizing the external volumes and enabling the shared use of such external volumes by a plurality of available virtualization storage devices. By virtualizing and incorporating the external volume of an external storage device, a first virtualization storage device is able to provide the volume to a host as though it is an internal volume. When the load of the first virtualization storage device increases, a second virtualization storage device 2 is newly introduced, and connected to the storage system. When a transfer direction is issued from a management terminal, the external volume relating to the selected logical volume is transferred from the first virtualization storage device to the second virtualization storage device.

1 . A storage system, comprising: 
 a plurality of connection source storage devices capable of respectively providing a logical volume to a host device;    a connection destination storage device respectively connected to each of said connection source storage devices and having a separate logical volume; and    a direction unit for directing the connection destination of said separate logical volume;    each of said connection source storage devices is configured to comprise:    a management information memory unit for storing management information for managing said separate logical volume; and    a control unit for connecting said logical volume and said separate logical volume via an intermediate volume based on said management information stored in said management information memory unit,    wherein the connection destination of said separate logical volume can be switched among each of said connection source storage devices based on the direction from said direction unit.    
   
   
       2 . The storage system according to  claim 1 , wherein the switching of the connection destination of said separate logical volume is to change the connection source storage device capable of exclusively using said separate logical volume among each of said connection source storage devices.  
   
   
       3 . The storage system according to  claim 1 , wherein the connection destination of said separate logical volume is switchable among each of said connection source storage devices without stopping the access from said host device to said logical volume.  
   
   
       4 . The storage system according to  claim 1 , wherein the access destination of said host device is switched among each of said connection source storage devices according to the switching of the connection destination of said separate logical volume.  
   
   
       5 . The storage system according to  claim 1 , wherein said management information is constituted by including first management information for specifying said separate logical volume, and second management information for managing the attribute of said separate logical volume; 
 said first management information is retained by each of said connection source storage devices; and    said second management information is retained by the connection source storage device of the switching destination selected as the connection destination of said separate logical volume.    
   
   
       6 . The storage system according to  claim 5 , wherein said first management information contains volume identifying information for specifying said separate logical volume in the storage system, usage authorization information for specifying the connection source storage device having usage authorization of said separate logical volume, and switching status information for showing whether the connection destination of said separate logical volume is being switched among each of said connection source storage devices; and 
 said second management information contains a plurality of pieces of other attribute information relating to said separate logical volume.    
   
   
       7 . The storage system according to  claim 6 , wherein said usage authorization information is set by the connection source storage device that becomes the switching source among each of said connection source storage devices, notified from the connection source storage device that becomes the switching source to the connection source storage device that becomes the switching destination, and the change of said usage authorization information is determined by the connection source storage device that becomes the switching source receiving the setting completion report from the connection source storage device that becomes the switching destination.  
   
   
       8 . The storage system according to  claim 1 , wherein, a switching status flag is set while the connection destination of said separate logical volume is being switched from the connection source storage device that becomes the switching source to the connection source storage device that becomes the switching destination, and said switching status flag is reset when the connection destination of said separate logical volume is switched; 
 while said switching status flag is being set, said connection source storage device that becomes the switching source destages unwritten data relating to said separate logical volume, and said connection source storage device that becomes the switching destination processes write data from said host device with an asynchronous system; and    when said switching status flag is reset, said switching destination storage device destages said write data.    
   
   
       9 . The storage system according to  claim 1 , wherein the connection source storage device that becomes the switching source among each of said connection source storage devices rejects the processing of access from said host device to said separate logical volume, and destages unwritten data relating to said separate logical volume.  
   
   
       10 . The storage system according to  claim 8 , wherein, when said destage is complete, said connection source storage device that becomes the switching source issues a destage completion report to the connection source storage device that becomes the switching destination; and 
 upon receiving said destage completion report, said connection source storage device that becomes the switching destination performs the processing of access from said host device to said separate logical volume.    
   
   
       11 . The storage system according to  claim 1 , further comprising a monitoring unit for monitoring the load status relating to at least the connection source storage device that becomes the switching source among each of said connection source storage devices.  
   
   
       12 . The storage system according to  claim 11 , wherein the connection source storage device that becomes the switching source and the connection source storage device that becomes the switching destination among each of said connection source storage devices are respectively selected based on the monitoring result of said monitoring unit.  
   
   
       13 . The storage system according to  claim 12 , further comprising a management terminal to be connected to each of said connection source storage devices, wherein said direction unit and said monitoring unit are respectively provided to said management terminal.  
   
   
       14 . A storage system having a plurality of connection source storage devices to be used by at least one or more host devices, and at least one or more connection destination storage devices to be connected to each of said connection source storage devices, wherein, 
 said host devise and each of said connection source storage devices are respectively connected via a first communication network, and each of said connection source storage devices and said connection destination storage device are connected via a second communication network separated from said first communication network;    said connection destination storage device has a separate logical volume to be logically connected to a logical volume of each of said connection source storage devices;    each of said connection source storage devices has a control unit for creating said logical volume and connecting said logical volume and said separate logical volume via an intermediate volume based on management information; and    a memory used by said control unit and for storing said management information;    said management terminal to be connected to each of said connection source storage devices has a monitoring unit for respectively monitoring the load status of each of said connection source storage devices, and a direction unit for respectively selecting the connection source storage device that becomes the switching source and the connection source storage device that becomes the switching destination among each of said connection source storage devices based on the monitoring result of said monitoring unit, and    switches the connection destination of said separate logical volume from the connection source storage device selected as said switching source to the connection source storage device selected as said switching destination based on the designation from said direction unit;    said management information is constituted by including first management information for specifying said separate logical volume, and second management information for managing the attribute of said separate logical volume, and said first management information is respectively stored in the connection source storage device selected as said switching source and the connection source storage device selected as said switching destination; and    the entirety of said second management information is stored in the connection source storage device selected as said switching source, and only the second management information relating to said separate logical volume in which the connection destination is switched is transferred from the connection source storage device selected as said switching source to the connection source storage device selected as said switching destination.    
   
   
       15 . The storage system according to  claim 14 , wherein the connection source storage device selected as said switching source rejects the processing of access from said host device to said separate logical volume, and destages unwritten data relating to said separate logical volume.  
   
   
       16 . The storage system according to  claim 15 , wherein, when said destage is complete, the connection source storage device selected as said switching source issues a destage completion report to the connection source storage device selected as said switching destination; and 
 upon receiving said destage completion report, said connection source storage device selected as said switching destination performs the processing of access from said host device to said separate logical volume.    
   
   
       17 . An operation method of a storage system having a first connection source storage device and a second connection source storage device capable of respectively providing a logical volume to a host device via a first communication network, and a connection destination storage device connected to each of said first and second connection source storage devices via a second communication network, comprising: 
 an initial operation step of respectively connecting said plurality of separate logical volumes to one or a plurality of logical volumes of said first connection source storage device via an intermediate volume of said first connection source storage device based on the management information for respectively connecting to a plurality of separate logical volumes of said connection destination storage device, and making said first connection source storage device process the access request from said host device;    a device addition step of connecting said second connection source storage device to said host device via said first communication network, to said connection destination storage device via said second communication network, and to said first connection source storage device via a third communication network;    a first management information transfer step for transferring information for respectively specifying said plurality of separate logical volumes among said management information of said first connection source storage device from said first connection source storage device to said second connection source storage device via said third communication network;    a transfer target selection step for selecting a separate logical volume to be transferred to said second connection source storage device among said plurality of separate logical volumes used by said first connection source storage device;    a second management information transfer step for transferring the attribute information relating to said separate logical volume selected as said transfer target among said management information of said first connection source storage device from said first connection source storage device to said second connection source storage device via said third communication network; and    an additional operation step for connecting said separate logical volume selected as said transfer target to the logical volume of said second connection source storage device via an intermediate volume of said second connection source storage device based on the information acquired at said first management information transfer step and said second management information transfer step, setting the path information for said host device to access said logical volume of said second connection source storage device in said host device, and making said second connection source storage device process the access request from said host device.    
   
   
       18 . The operation method of a storage system according to  claim 17 , wherein at said transfer target selection step, all separate logical volumes used by said first connection source storage device are selected as said transfer target; and 
 a device replacement step is further executed after said additional operation step, and, at said device replacement step, said first connection source storage device is separated from said host device, said first connection source storage device is separated from said second connection source storage device, and said first connection source storage device is separated from said connection destination storage device.