Techniques for accessing remote files

Abstract

Techniques for accessing remote files are presented. A local user, via a local client, requests access to a file. A local file system determines that the file is associated with a junction. The junction is resolved and an associated remote file system is contacted by the local file system to acquire results for the request. The local file system then delivers the results to the local user via the local client.

1 . A machine-implemented method, comprising:
 receiving a request to access a file from a client, wherein the request is received at a local file system, which processes on a server and which supports the client and multiple additional clients associated with a local processing environment;   resolving a path to the file across a network as a junction;   looking up the junction to find a remote file system over the network that has the file and that is accessible via the path;   contacting the remote file system over the network with the request for access to the file;   acquiring results associated with the request to access the file from the remote file system; and   delivering the results to the client.   
   
   
       2 . The method of  claim 1 , wherein resolving further includes maintaining within the local file system a mechanism to resolve the junction and other junctions associated with other remote file systems within a volume lookup database instead of maintaining mount points for the remote file system and the other remote file systems. 
   
   
       3 . The method of  claim 2 , wherein resolving further includes searching the volume lookup database with an identifier for the file, wherein the identifier is supplied with the request from the client. 
   
   
       4 . The method of  claim 2 , wherein resolving further includes processing the local file system as a flexible user space file system that looks for and discovers the junction. 
   
   
       5 . The method of  claim 4 , wherein resolving further includes recognizing the junction as a distributed file service junction. 
   
   
       6 . The method of  claim 1 , wherein contacting further includes using a different protocol from that which was used by the client to make the request when contacting the remote file system. 
   
   
       7 . The method of  claim 1  further comprising, subsequently detecting a change in the path for the file and updating a mapping associated with the junction to reflect the change within the local file system. 
   
   
       8 . A machine-implemented method, comprising:
 servicing file requests from multiple clients associated with multiple users from a server associated with a local processing environment;   detecting when a particular request is associated with a distributed file service (DFS) junction for a remote file system that manages a particular file;   interacting with the remote file system on behalf of a particular user associated with the particular file to process the particular request; and   delivering results from interacting with the remote file system back to a particular client associated with the particular user.   
   
   
       9 . The method of  claim 8 , wherein detecting further includes recognizing the DFS junction as an identifier for the remote file system and a path within a remote processing environment of the remote file system to access the particular file. 
   
   
       10 . The method of  claim 8 , wherein detecting further includes searching a volume lookup database within the local processing environment with an identifier for the particular file to resolve the DFS junction. 
   
   
       11 . The method of  claim 10  further comprising, updating the volume lookup database when a change to a file location for a particular DFS junction is noted, and wherein the change is immediately available to each of the users and each of the clients within the local processing environment. 
   
   
       12 . The method of  claim 8 , wherein detecting further includes recognizing that the remote file system is not locally mounted within the local processing environment. 
   
   
       13 . The method of  claim 8 , wherein interacting further includes interacting with the remote file system via communications that are transparent and unknown to the particular user and the particular client associated with the particular user. 
   
   
       14 . The method of  claim 8 , wherein interacting further includes using a server-to-server communication protocol to interact with the remote file system. 
   
   
       15 . A machine-implemented system, comprising:
 a local file system service implemented in a machine-accessible and computer-readable storage medium on a server of a network; and   a volume lookup database implemented in a machine-accessible and computer-readable storage medium on the server of the network and accessible to and managed by the local file system service;   wherein the local file system service is implemented within a local file system that processes on the server and that services multiple users via their clients and authenticates the users, and wherein the local file system service resolves file requests to particular remote file systems via searching of the volume lookup database and wherein the local file system service further directly interacts with those remote file systems to satisfy the file requests on behalf of the users and their clients.   
   
   
       16 . The system of  claim 15 , wherein the volume lookup database includes mappings between volume identifiers for files and the remote file systems. 
   
   
       17 . The system of  claim 16 , wherein the mappings are represented as and used to resolve distributed file service (DFS) junctions. 
   
   
       18 . The system of  claim 17 , wherein when a particular location for a particular file associated with a particular file requests is changed, the local file system service updates a single entry in the volume lookup database to show an updated particular DFS junction via a mapping from a particular volume to the particular file to a new particular location. 
   
   
       19 . The system of  claim 15 , wherein the local file system is a flexible user space file system. 
   
   
       20 . The system of  claim 15 , wherein the local file system service uses different communication protocols to communicate with the remote file systems from that which is associated with the local file system service when it communicates with the clients of the users. 
   
   
       21 . A machine-implemented system, comprising:
 a local file system service implemented in a machine-accessible and computer-readable storage medium and to process on a local server of a network relative to users and their clients; and   a remote file system service implemented in a machine-accessible and computer-readable storage medium and to process on a remote server of the network relative to the local server;   wherein when a file is requested from a particular client, the local file system service determines that the file is being managed by the remote file system service and directly communicates with the remote file system service to acquire results for the requested file, which the local file system service delivers to the particular client.   
   
   
       22 . The system of  claim 21 , wherein the local file system service determines an identity for the remote file system service via a distributed file service (DFS) junction lookup within a data store being managed locally by the local file system service. 
   
   
       23 . The system of  claim 21 , wherein the local file system service uses a different communication protocol to communicate with the remote file system service from that which is associated with other communications made with the clients. 
   
   
       24 . The system of  claim 21 , wherein the particular client is unaware of the communication between the local file system service and the remote file system service that occurs to obtain the results.