TCP IP Illustrated

This implementation technique puts all the mount

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Unformatted text preview: . 3. The port mapper replies with the port number. 4. The mount command issues an RPC call to the mount daemon to mount a filesystem on the server. Again, either TCP or UDP can be used, but UDP is typical. The server can now validate the client, using the client's IP address and port number, to see if the server lets this client mount the specified filesystem. 5. The mount daemon replies with the file handle for the given filesystem. 6. The mount command issues the mount system call on the client to associate the file handle returned in step 5 with a local mount point on the client. This file handle is stored in the NFS client code, and from this point on any references by user processes to files on that server's filesystem will use that file handle as the starting point. This implementation technique puts all the mount processing, other than the mount system call on the client, in user processes, instead of the kernel. The three programs we show-the mount command, the port mapper, and the mount daemon-are all user processes. As an example, on our host sun (the NFS client) we execute sun # mount -t nfs bsdi:/usr /nfs/bsdi/usr This mounts the directory /usr on the host bsdi (the NFS server) as the local filesystem /nfs/bsdi/usr. Figure 29.6 shows the result. file:///D|/Documents%20and%20Settings/bigini/Docu...homenet2run/tcpip/tcp-ip-illustrated/nfs_netw.htm (11 of 23) [12/09/2001 14.47.56] Chapter 29. NFS: Network File System Figure 29.6 Mounting the bsdi:/usr directory as /nfs/bsdi/usr on the host sun. When we reference the file /nfs/bsdi/usr/rstevens/hello.c on the client sun we are really referencing the file /usr/rstevens/hello.c on the server bsdi. NFS Procedures The NFS server provides 15 procedures, which we now describe. (The numbers we use are not the same as the NFS procedure numbers, since we have grouped them according to functionality.) Although NFS was designed to work between different operating systems, and not just Unix systems, some of the procedures...
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This test prep was uploaded on 04/04/2014 for the course ECE EL5373 taught by Professor Guoyang during the Spring '12 term at NYU Poly.

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