File permission getting read only

[Swapana Ghosh <swapana_ghosh yahoo com>]

Hi all,

I am not sure this is the problem  of NAS (nfs) or the File system, I am sending my problem to this list though.  If this is wrong list for my post , then I do aplogise.

Here is the problem in brief:

   -  The server is rhel4.

   -  One file system (NAS) has been exported. 

   -  The file system has been mounted in the server. The mount point is  like as 

        nas2.xxx.org:/dev/deg/temp       /apps/deg/dev  

   -  I am doing 

          cd  /apps/deg/dev and , creating some file say  xx. File is
          being created withthe  the file permission   644  .

          Then I am changing the file permission as  444 as root.
          After that when if I try to change the permission of the xx 
          file back to 644 or anything , it is giving 
          "permission denied".  I can't do any updates on xx file. 

   -  Same type of process I am doing on a  simililar type of NAS 
      mounted file system , it is perfectly alright.

If anyone gives me some pointers  that will be really appreciated.

Thanks in advance