Operation method of storage and storage and remote storage used therein

Abstract

An operation method of a storage wherein when a storage detects that a remaining amount of its own storage area has become less than a predetermined value, a remote storage area provided by a remote storage connecting with said storage via a predetermined communication means may be used as said storage area.

What is claimed is:  
     
         1 . An operation method of a storage wherein when a storage detects that a remaining amount of its own storage area has become less than a predetermined value, a remote storage area provided by a remote storage connecting with said storage via a predetermined communication means may be used as said storage area.  
     
     
         2 . An operation method of a storage according to  claim 1 , wherein specifications such as a size and a logic format of said remote storage area to be utilized are notified by said communication means from said storage to said remote storage, and said remote storage provides said remote storage area comprising said specifications as the storage area of said storage.  
     
     
         3 . An operation method of a storage according to  claim 1 , wherein data or file with low utilization frequency is stored and managed with priority in said remote storage area.  
     
     
         4 . An operation method of a storage according to  claim 1 , wherein a utilization state of said remote storage area of said storage is monitored in said remote storage, and whether or not said storage area in said storage is to be increased is decided according to said utilization state.  
     
     
         5 . An operation method of a storage according to  claim 1 , wherein data stored and managed in said remote storage area is copied to the storage area of said storage when the storage area of said storage is enlarged.  
     
     
         6 . An operation method of a storage according to  claim 1 , wherein a utilization record of said remote storage area of said storage is stored and managed in said remote storage, and a utilization cost of said remote storage area is to be calculated based on said utilization record.  
     
     
         7 . A storage used in an operation method of a storage according to either one of  claims 1  to  5 , comprising one or more disk units constituting said storage area, and a communication interface for communicating with said remote storage.  
     
     
         8 . A remote storage used in an operation method of a storage according to either one of  claims 1  to  5 , comprising one or more disk units constituting said remote storage area, and a communication interface for communicating with said storage.