Server without any video card

Hello !!

I need to buy and install a powerfull linux computing server machine for image processing applications, but I have some doubts concerning the X11. The problem is that a server machine usually is not coming with a Video card (or it has a simple one), so I was wondering :

1) if could be possible to install the X11 in the computing server (without any video card) in order to open remotely graphical applications (i.e. GUI) needed for the data management and visualization ?

2) If I install a "poor/cheap" video card in order to be able to install X11 on the server, and run remotely a GUI application from my workstation with a powerful video card, which video resolution will be used, the server resolution or client resolution and capabilities ?


I hope somebody can help me with my doubts.

Thanks,
JM

You can set up an ethernet port as a remote console, or use a serial port connected to a dumb terminal (or a PC running a terminal emulator, such as Linux running minicom).

Quote:

---

Originally Posted by ppmim

2) If I install a "poor/cheap" video card in order to be able to install X11 on the server, and run remotely a GUI application from my workstation with a powerful video card, which video resolution will be used, the server resolution or client resolution and capabilities ?


I hope somebody can help me with my doubts.

Thanks,
JM

---

What you see will be X rendered locally while the program is actually running on the server. In other words it will use the resolution set by the local / workstation computer.

Quote:

---

Originally Posted by ppmim

Hello !!

I need to buy and install a powerfull linux computing server machine for image processing applications, but I have some doubts concerning the X11. The problem is that a server machine usually is not coming with a Video card (or it has a simple one), so I was wondering :

1) if could be possible to install the X11 in the computing server (without any video card) in order to open remotely graphical applications (i.e. GUI) needed for the data management and visualization ?

2) If I install a "poor/cheap" video card in order to be able to install X11 on the server, and run remotely a GUI application from my workstation with a powerful video card, which video resolution will be used, the server resolution or client resolution and capabilities ?


I hope somebody can help me with my doubts.

Thanks,
JM

---

If you plan to secure shell into a powerful server from a machine that has a X-server running, then all you need is to install the X-server (Gnome,KDE, etc optional unless you plan on using some apps written using them) on the server. Then you secure shell into the server using the "-XY" options like:

Code:

---

ssh -XY usernameonserver@serverhost

---

That is the great feature of X than has been there at least since 1984 (which pre-dates ssh) and this is what citrix was attempting to provide in the Window arena much much later.

So basically, you want to be able to run X-Window sessions from other systems to the server? With X-Windows, like RDP, as mentioned by ProfTheory, the resolution of the X session is determined by the client.

To connect a standard X-Client like Xorg, Xnest, or Xephyr to a server, the server must be running at run level 5 (X-Windows), with XDMCP listening (UDP Port 177) on at least one NIC of the server. This requires a working and running local X-Window session. These clients provide very good displays on a LAN, but are very slow if connecting via a WAN.

Most servers have a least a basic VGA integrated video card, and X should work at least at 1024x768. This is all you need to allow any standard X-Client to connect at whatever resolution the client supports. Most current distros can run X-Windows by auto-detecting the video, so you may not need to create a xorg.conf file, but if you do, many sites have examples of basic xorg.conf files, and your distro likely has a tool to create one, too.

Personally, I always use a video card, especially with server hardware that has RAID, SCSI and other hardware with their own bios/firmware programs. Unless there is a remote hardware management module in the server, it can be pretty hard to diagnose boot issues without a console.

If, for some reason, the built-in video doesn't work with X-Windows, Xorg has a 'dummy' driver that makes a mock video card in memory, so X-Windows can be run without a video card or monitor. There is no output with the dummy driver, so even if you have monitor connected, it will go blank when X is started using the 'dummy' driver. For this to work, you will need a basic xorg.conf specifying:
Driver 'dummy'
in the Device section.

There is another X server called the NoMachine NX server. This server creates X-Sessions over SSH tunnels and works at run level 3; therefore, you don't need a working local X-Session. It only works with the NX Client, and provides slightly less display quality, but maintains usability over pretty much any connection.
To install the NX Server, first try using packages created for your distro, as it is the easiest way to go. Look for nx-... and/or freenx-server... packages in your repositories. Otherwise NX is available at the NOMachine web site.
NX Clients are available for Linux, Mac, and Windows.

Hope it helps.

Ohhh, guys, you're so fast !
If I where you I would simply avoid this kind of configuration because of the laggies of the frame buffer when generated by a simple X proccess in memory by the CPUs, and afterall, if you are planning to use OpenGL apps, sorry, until we have the final free OpenGL drivers for Nvidia or ATI, better use one of those cards with their respective blobs (sorry again...), the video cards framebuffers from ATI and Nvidia will always render images faster than most of processors in memory. Another case is when you need total precise results. (Comformant Image Rendering) But even in this case, I don't know exactly what kind of app you will use, but you have also the option for OpenCL programming for image processing, wich will give you faster results without sacrificing precision. Some OpenGL processing and rendering in different videocards could possibly give you different results because of the algorithms, but CPUs and OpenCL processors are very precise.

Video Card's are faster for image processing as a CPU and they can process much more parallel. Maybe you can plug two or three in your server.

First of all, thank you for your useful posts !

Yes, what I want is to be able to run X-Window sessions from other systems to the server, to run a GUI application quite simple (with File, Edit, Config, etc menus), and with no major GPU processing because the image processing is done by the CPU.

So, following your comments I will get a simple but enought Video card for the server in order to install X11, and then the client will be who provide me a better resolution for the GUI and image display, doing locally the required rendering, isn't it ?
However, I still have some doubts about, because the server will have to do some graphics using a python libs (matplotlib), and maybe it needs some GPU capabilities.

Thanks again !

JM

When you run your apps via an X client the server will only be passing the instructions to the client in raw binary form while the remote client will be doing the work of rendering it.

If I get the scenario correct the server will be rendering video to a file while the client machine will be displaying the GUI for the application you'll be using?