Method for file level remote copy of a storage device

Abstract

An object of remote copy can be specified in units of a file or a directory more detailed than in units of a volume. If a host computer issues a write request of a file to NASa, NASa references a source NAS of remote copy and a source directory of remote copy at each entry on a copy file table and determines whether the file to be written is an object of remote copy; if it is determined to be an object of remote copy, the file to be written is remotely copied to a target directory of remote copy of a target NAS thereof.

1 . A file level copy method in at least one storage devices connected to a computer via a network, comprising the steps of: 
 receiving a write request from said computer to a file;    retaining information for specifying a remote copy destination in units of a file or a directory; and    executing a remote copy operation of said file to another storage device accessible via said network on the basis of said information.    
   
   
       2 . A method according to  claim 1 , further comprising retaining information for specifying an emergency remote copy destination in case of a failure of remote copy to said remote copy destination in addition to said information.  
   
   
       3 . A computer system, comprising: 
 at least one computers;    at least one storage devices; and    a network for connecting said computers and said storage devices with each other;    wherein, said storage device accepts a write request from said computer to a file, retains information for specifying a remote copy destination in units of a file or a directory, and executes a remote copy operation of said file to another storage accessible via said network.    
   
   
       4 . A system according to  claim 3 , further comprising means for inputting information for specifying said remote copy destination.  
   
   
       5 . A system according to  claim 4 , wherein said computer has means for inputting information for specifying said remote copy destination.  
   
   
       6 . A system according to  claim 4 , wherein said storage device has means for inputting information for specifying said remote copy destination.  
   
   
       7 . A system according to  claim 3 , wherein remote copy destinations of files individually stored in at least two volumes are set to an identical volume.  
   
   
       8 . A system according to  claim 3 , wherein remote copy destinations of two files stored in an identical volume are set to different volumes.