[Paraview] Can pvserver run without X server?

[Weiguang Guan]

Hi Kent,

I cannot answer your first question as I am new to DRI too. For your 
second question, we have quite a few computing clusters purchased with 
Sharcnet funding (www.sharcnet.ca). These clusters don't run X as their 
main usage is "pure computation" --- scientific simulations and analysis, 
etc. However, graphics card is installed in each node of the clusters, and 
is not exploited at all. We were wondering if we could turn the "computing 
cluster" into "rendering cluster"...... That's why I'm so interested in 
DRI.

Thank you for your thought.

Weiguang

On Wed, 14 Mar 2007, Kent Eschenberg wrote:

> Very interesting! It looks like you are right.
>
> The important question is whether ParaView and/or VTK must make additional 
> calls to use the DRI approach - is there a need to call, for example, 
> something like "DRI_Initialize"? If so you'll need to figure out where to put 
> those new calls.
>
> How do you come to have a system with a graphics card but no X server?
>
> Kent
>
> Weiguang Guan wrote:
>> Thanks for the instant responses.
>> 
>> I've already built Paraview with OSMesa and run it with offscreen rendering 
>> option on a cluster without X.
>> 
>> However, I want Paraview do the rendering using GPU rather CPU as rendering 
>> with GPU is about 10-20 times faster than with CPU. If DRI has been adapted 
>> to provide OpenGL acceleration without an X Server running (ref 
>> http://en.wikipedia.org/wiki/Direct_Rendering_Infrastructure), then it is 
>> possible (theoretically at least) to avoid X server and at the same time 
>> enjoy video hardware acceleration. Am I right?
>> 
>> Weiguang
>> 
>> On Wed, 14 Mar 2007, Moreland, Kenneth wrote:
>> 
>>> You should be able to use the OSMesa library to open a software-emulated
>>> OpenGL context without connecting to an X host.  If you compile with the
>>> OSMesa library and then use the offscreen command line option on the
>>> client, then you can render and composite on the server without an X
>>> host there.
>>> 
>>> We have been doing that for years with ParaView 2.X.  If it does not
>>> work with ParaView 3, that would be a bug.
>>> 
>>> -Ken
>>> 
>>>> -----Original Message-----
>>>> From: paraview-bounces+kmorel=sandia.gov at paraview.org
>>> [mailto:paraview-
>>>> bounces+kmorel=sandia.gov at paraview.org] On Behalf Of Kent Eschenberg
>>>> Sent: Wednesday, March 14, 2007 11:33 AM
>>>> To: Weiguang Guan
>>>> Cc: ParaView
>>>> Subject: Re: [Paraview] Can pvserver run without X server?
>>>> 
>>>> Weiguang Guan wrote:
>>>>> Has anyone run Paraview in client/server mode where the pvserver run
>>> on
>>>>> a computer (or cluster) without X server running? It seems to me
>>> that
>>>>> DRI can let an application access video hardware directly without
>>> going
>>>>> through X server.
>>>> 
>>>> I think the answer is no. When composite is off the client does the
>>>> rendering and the graphics card has to be at the client. When
>>> composite
>>>> is on the server does the rendering but it only works through OpenGL
>>> or
>>>> through Mesa which emulates OpenGL.
>>>> 
>>>> I think both must reach the graphics card through the X server. In
>>> other
>>>> words, the X server "owns" the graphics card and manages all access to
>>> it.
>>>> 
>>>> The last system I know of that would do what you wanted was from SGI
>>>> using their GL language, the precursor to OpenGL.
>>>> 
>>>> Kent
>>>> Pittsburgh Supercomputer Center
>