Method, apparatus, and program for separate representations of file system locations from referring file systems

Abstract

A system provides referencing from one file system server to another through the use of a file system location database improving movement and replication of file systems. When a file system is moved from a first file system server a data object that references the file system remains in the first server and contains information used to find the current location of the file system. The actual location of the file system is stored in the separate file system location database which contains the locations of file systems on a number of file system servers. This allows the data in a file system to be replicated or moved without requiring updates to the data in any redirecting or referencing servers.

1 . A method, in a network including a requested file system server, for servicing a request, comprising: 
 receiving a request for a referencing object from a client, wherein the referencing object refers to a referenced file system;    looking up a location of the referenced file system in a separate data structure at a remote location; and    returning a redirection message indicating the location of the referenced file system to the client.    
   
   
       2 . The method of  claim 1 , wherein the redirection message includes an address of a referenced file system server.  
   
   
       3 . The method of  claim 2 , wherein the redirection message further includes a path.  
   
   
       4 . The method of  claim 2 , wherein the referencing object has a file system identifier.  
   
   
       5 . The method of  claim 4 , further comprising: 
 encoding the file system identifier, wherein the redirection message further includes the encoded file system identifier.    
   
   
       6 . The method of  claim 5 , wherein the referencing object is a top level object for a uniform namespace including all file systems on participating file system servers.  
   
   
       7 . The method of  claim 2 , wherein the referenced file system server is the requested file system server.  
   
   
       8 . The method of  claim 1 , wherein the separate data structure comprises a file system location database.  
   
   
       9 . The method of  claim 1 , further comprising: 
 receiving a redirected request for a file system object;    identifying an encoded file system identifier in the redirected request;    decoding the encoded file system identifier to form a file system identifier corresponding to a requested file system;    looking up a path for the requested file system in a file system identifier data structure at a second remote location; and    retrieving the root of the requested file system using the path for the requested file system.    
   
   
       10 . The method of  claim 9 , wherein the file system identifier data structure comprises a file system identifier table.  
   
   
       11 . The method of  claim 9 , wherein the separate data structure and the file system identifier data structure are stored in a file system location database.  
   
   
       12 . The method of  claim 1 , wherein the referencing object is a top level object for a uniform namespace including all file systems on participating file system servers.  
   
   
       13 . A method, in a network including a requested file system server, for servicing a request, comprising: 
 receiving a request for a file system object, wherein the request includes an encoded file system identifier;    decoding the encoded file system identifier to form a file system identifier corresponding to a requested file system;    looking up a path for the requested file system in a file system identifier data structure at a remote location; and    retrieving the root of the requested file system using the path for the requested file system.    
   
   
       14 . The method of  claim 13 , wherein the file system identifier data structure is stored in a table.  
   
   
       15 . The method of  claim 13 , wherein the file system identifier data structure is stored in a file system location database at the remote location.  
   
   
       16 - 30 . (canceled)  
   
   
       31 . A computer program product, comprising: 
 a computer usable medium including computer usable program code for servicing a request, said computer program product including:    computer usable program code for receiving a request for a referencing object from a client, wherein the referencing object refers to a referenced file system;    computer usable program code for looking up a location of the referenced file system in a separate data structure; and    computer usable program code for returning a redirection message indicating the location of the referenced file system to the client.    
   
   
       32 . A computer program product of  claim 31  further comprises: 
 computer usable program code for receiving a request for a file system object, wherein the request includes an encoded file system identifier;    computer usable program code for decoding the encoded file system identifier to form a file system identifier corresponding to a requested file system;    computer usable program code for looking up a path for the requested file system in a file system identifier data structure; and    computer usable program code for retrieving the root of the requested file system using the path for the requested file system.    
   
   
       33 . The method of  claim 1  further comprises: 
 receiving relocate request for relocating the referenced file system;    relocating the referenced file system to a relocation file system server;    replacing the referenced file system with the referencing object, wherein the referencing object excludes an address for the relocation file system server; and    updating an attribute for the referenced file system in the separate data structure with the address for the relocation file system server.    
   
   
       34 . The computer program product of  claim 31  further comprises: 
 computer usable program code for receiving relocate request for relocating the referenced file system;    computer usable program code for relocating the referenced file system to a relocation file system server;    computer usable program code for replacing the referenced file system with the referencing object, wherein the referencing object excludes an address for the relocation file system server; and    computer usable program code for updating an attribute for the referenced file system in the separate data structure with the address for the relocation file system server.    
   
   
       35 . A system of servicing a request, the system comprising: 
 a file system server comprising: 
 a memory to store addresses of remotely located data structures;  
 a network adapter connected to a network to transmit and receive messages on the network;  
 a processor to process a request for a referencing object from a client, to look up an address of a location for a separate data structure in the memory, to issue a request for a location of the referenced file system to the address of a location for the separate data structure, and to issue a redirection message indicating the location of the referenced file system to the client; and  
 a bus to communicate between the processor, memory and network adapter.  
   
   
   
       36 . The system of  claim 35 , wherein the redirection message includes an address of a referenced file system server.  
   
   
       37 . The system of  claim 36 , wherein the redirection message further includes a path.  
   
   
       38 . The system of  claim 36 , wherein the referencing object has a file system identifier.  
   
   
       39 . The system of  claim 38 , wherein the processor encodes the file system identifier, and the redirection message further includes the encoded file system identifier.  
   
   
       40 . The system of  claim 35 , further comprising: 
 a second file system server comprising: 
 a memory to store addresses of remotely located data structures;  
 a network adapter to receive and transmit messages on a network;  
 a processor to process a redirected request for a file system object, identify an encoded file system identifier in the redirected request, decode the encoded file system identifier to form a file system identifier corresponding to a requested file system, to look up an address of a location for a file system identifier data structure in the memory, to issue a request for a path for the requested file system in the file system identifier data structure, and retrieve the root of the requested file system using the path for the requested file system, and a bus to communicate between the processor, memory and network adapter.