[Discuss] FreeNx

[Jeremy Kiffiak]

On 20-Nov-07, at 4:42 PM, John Blomfield wrote:

> Alan W. Irwin wrote:
>> On 2007-11-20 11:05-0800 Michael wrote:
>>
>>> On Tue, 2007-11-20 at 10:49 -0800, Alan W. Irwin wrote:
>>>
>>>> On 2007-11-20 10:06-0800 Michael wrote:
>>>>
>>>>>> I think of FreeNX as a way to accelerate X communications over  
>>>>>> a low
>>>>>> bandwidth high-latency network.  In practice, though, I find  
>>>>>> it is not
>>>>>> needed for typical home LAN speeds of 100Mb/s.  For example,  
>>>>>> for our
>>>>>> thin-client configuration (X-terminal), we don't bother with  
>>>>>> it because
>>>>>> there is no noticable difference in X access speed locally or  
>>>>>> over our
>>>>>> 100Mb/s LAN.
>>>>>>
>>>>>> Let's call your boxes, box1, box2, and box3 ... // ......  
>>>>>> simply be a matter of
>>>>>> hitting ctrl-alt-F7, ctrl-alt-F8, or ctr-alt-F9.  X networking  
>>>>>> support is
>>>>>> truly empowering!
>>>>>>
>>>>>> Alan
>>>>>
>>>>>
>>>>>    Am I understanding this correctly? Can I actually operate  
>>>>> various
>>>>> headless systems via remote X sessions using FreeNX?
>>>>
>>>> Actually, that capability has been built right into X for  
>>>> decades so there
>>>> is no need to bother with FreeNX unless you are in a low-bandwidth
>>>> (internet) situation.  100Mb/s LAN's have plenty of speed so the  
>>>> FreeNX
>>>> complication is not required to run X applications (e.g., KDE)  
>>>> on any of the
>>>> boxes on your LAN with a monitor/keyboard mouse combination  
>>>> permanently
>>>> connected to just one of them.
>>>>
>>>> Alan
>>>
>>>
>>>    This is extremely interesting! The things I learn every day.  
>>> What is
>>> this functionality called? I have never researched the x server  
>>> at all,
>>> so I wouldn't have the first clue what to look for. I will start
>>> searching under "remote X sessions", but if it actually has a  
>>> specific
>>> name, things will certainly go faster.
>>
>> This method is used to enable so-called thin clients or X  
>> terminals which
>> run the X server (which controls the monitor, mouse, and keyboard)  
>> locally
>> and X applications (such as KDE or GNOME) remotely on a headless (but
>> extremely powerful) box.  Normally, only one headless box is  
>> involved when
>> dealing with thin clients, but there is no reason why you cannot  
>> have just
>> one fat client (with thin client capability) displaying X application
>> results from a number of headless boxes as well as X application  
>> results
>> from itself.
>>
>> To give you some background, The city of Largo Florida has used the
>> thin-client approach where the ~500 city employees use thin  
>> clients to run
>> GNOME on one central server.  Dave Richards is in charge there,  
>> and you can
>> read his blog (http://davelargo.blogspot.com/) to see how it is  
>> going for
>> his second-generation 3D thin-client effort.
>>
>> Another X-terminal general reference is ltsp.org.  But that is  
>> focussed
>> on all the details required for booting diskless thin clients, and  
>> since you
>> don't have to worry about diskless, you could get easily get lost in
>> those details.
>>
>> Assuming you already have Linux running on all your headless boxes  
>> and your "headed" box, all that is really required is to set up  
>> xdm (X display
>> manager) on each headless box, and to run "X -query" on your  
>> headed box.
>> There is an X display manager entry for wikipedia at
>> http://en.wikipedia.org/wiki/X_display_manager which gives you  
>> some of the
>> background.  I mentioned xdm configuration details in
>> http://ladybug.vlug.org/pipermail/discuss/2007-November/ 
>> 023941.html.  Those
>> details are quite simple.  But you should also consult the xdm man  
>> page as
>> well since some of those details might be set up differently on your
>> particular distribution.
>>
>> There are other X display managers than xdm (e.g., gdm, kdm, ldm),  
>> but to my
>> mind they all overcomplicate a simple task (to respond over the  
>> network to X
>> -query).  So I far prefer xdm over the others.
>>
>> Alan
> I am still trying to decide how best to proceed with my three boxs,  
> that is, X-xdm, freeNx or some other but I have a question about  
> the X-xdm route.  If once you've setup your X headless server and  
> the network connection to the thin (or fat ) client is broken can  
> you still plug a keyboard, mouse and monitor into the server and  
> get it to work, now that you've modified the display manager??
>
> John Blomfield

John,

Absopolutely (yes that was intentional...).  The "server" system can  
be running X and therefore if you plug a monitor in to it you will  
get a normal X login window.  Running the server headless is more to  
save space and and energy.  The LTSP project that Alan mentioned  
earlier is also something worth looking at.  It is pretty simple to  
get up and going and has some nice management tools bundled with it  
(at least in Ubuntu).

Jeremy