on backend I have /myth/video/Maxtor directory

on client I have mounted the directory in the same directory on the client.

I can see and browse the files from the client, but, when I try to play the files in the mythtv client- nothing happens ? what am I doing wrong ?

You can "see and browse the files" from within Myth, or on the command line? Is your client pointing to /myth/video/Maxtor in Utilities/Setup -> Setup -> Media Settings -> Videos Settings -> General Settings? And in what way do you have this directory mounted?

I can see and browse files from both the commandline, and in the mythtv frontend (client).
Setup is pointing to the Maxtor directory.

I hope I followed :
http://knoppmythwiki.org/index.php?page=NFSHowTo

for setting it up.

Most likely a permissions issue then. What is the permisson structure on /myth/video/Maxtor on the "client" side? ls -lR /myth/video/Maxtor will give you a recursive listing.

-r-x------ 2 mythtv mythtv

for all files in the directory - is that OK ?

That's from the client side? Should be OK, I think. That gives the mythtv user read and execute permissions. What happens if you change perms to 544?

Try playing one of them with Xine (I assume you are using the internal player, as you said it does "nothing") - You'll get some errors out of it anyway...

EDIT: What are the permissions on the directories leading to the videos? (/myth, /myth/video, /myth/video/Maxtor) /EDIT

played files using VLC and Xine - but not mplayer !

changed player parameter to x11 insted of xv.... that did the trick !