ALIs

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Detailed step-by-step procedure for first-time users

1. Install TurboVNC on your client PC

The TurboVNC software is needed to relay the graphics from the remote visualisation system to your client PC (VNC stands for Virtual Network Computing and is needed for the so-called 'remote desktop'; to get the best graphics throughput over the internet, we use TurboVNC). TurboVNC is free software and you can download it here (there is a .dmg for Mac OS, .rpm, .deb and .tgz for Linux, and .exe for Windows). Under Windows, run the executable as administrator to install TurboVNC (you only need to install "TurboVNC Viewer"). (For the advanced user: Yes, there are many different VNC servers and VNC viewers out there. TurboVNC, however, is best suited for heavy graphics throughput.)

2. Connect to the remote visualisation system

The remote visualisation servers are only available for the Linux cluster. The name of the server is 

gvs3, or gvs4

If you are using Mac OS or Linux, open a terminal and type

$ ssh lx64ia2.lrz.de
and then 
$ ssh gvs3.cos.lrz.de
Windows user can use putty (putty is free software and you can get it here).

3. Set a VNC password

The first time you log-on to the remote visualisation server, you have to set a password for VNC. To do this, type

gvs3:> vncpasswd

at the command prompt. Type a password and verify it by entering it a second time. This password is needed in step 7 and every time you want to connect to the remote desktop on the remote visualisation system! You will then be asked

Would you like to enter a view-only password (y/n)?

If you answer yes ("y"), you will be asked for another VNC password. You can give this password to co-workers, so that they can log-on to your VNC session, e.g. to discuss new results over the phone. Your co-workers will see what you see, but their inputs will be ignored. If you don't know "what sharing a VNC session" means, we recommend that you answer no ("n").

4. Start the remote desktop

At the command prompt of the remote visualisation server, enter:

gvs3:~> rvnc

You will see output on the console that will look similar to this:

New 'X' desktop is gvs3:4

This tells you that everything is fine and you can now connect to the remote desktop from your client. Make sure to write down the so-called 'display number', which will be an integer starting with 1 You will need this number in the next step to tell your client PC where to connect to.

Important note: Typing the command "rvnc" is the most simple way to try out the remote visualisation service. You will get a remote desktop with a desktop size of 1000x700 pixel for the rest of the day until 4:00 in the morning of the next day.

5. Start the TurboVNC viewer on your client PC

After you know your display number, you can start the TurboVNC viewer on your client machine. Linux users can type 

vncviewer -via lx64ia2.lrz.de gvs3:4
into a terminal window and will get a desktop window.

If you are using Windows, you have to establish a tunnel through the LRZ firewall, because the gvs cluster is no longer accessible from the outside. For establishing a tunnel start PuTTY and click on Connection/SSH/Tunnels. In the input field "Source port" enter 5901 and in the field "Destination" enter gvs3.cos.lrz.de:4, if 4 was the above display number. Then click on the button "Add". Then login to lx64ia2.lrz.de with PuTTY and you have established a tunnel.

In the input field for the VNC server Connection enter: "localhost:1" and press enter or click 'Connect'. This will then provide you with a login to the remote visualisation server.

Next, you will be asked for your TurboVNC password. If your password is correct, you should see a window appear that shows your desktop on the remote visualisation system.
(You can even give this string to a co-worker, who can then connect to the same session to work collaboratively on the same data set!)

Screenshot of the remote visualisation server's desktop

6. Visualize your data

Finally, you can do what you came here for! The remote desktop you just connected to will be yours for the next morning at 4:00. Open a terminal window and enter the command to start the visualisation application. 

$ rv run_vmd.sh
The following applications are available at the moment: 
$ rv run_amira.sh
$ rv run_drishti.sh
$ rv run_idl.sh
$ rv run_pymol.sh
$ rv run_vapor.sh
$ rv run_visit.sh
$ rv run_vmd.sh
$ rv run_tecplot.sh (with valid license)
The list will grow as new software packages will be installed.

Note:

The application will run until you exit it or for the next 12 hours or until 4:00 in the morning when all vncservers are terminated.

Want to have a bigger desktop? Typing the command "rvnc" is the most simple way to try out the remote visualisation service. You will get a remote desktop for one hour and with a desktop size of 1000x700 pixel. If you want to work on a bigger desktop, you can use a command similar to this:

rvnc -geometry 1600x1100.

This would give you a remote desktop with a desktop size of 1600x1100 pixel.

Information about the state of the remote visualisation cluster

You can find out about the general availability of the GPUs in the gvs cluster by using the command 

$ sinfo
PARTITION    AVAIL  TIMELIMIT NODES STATE  NODELIST
gvs_inter*   up      12:00:00     2 alloc  gvs[3-4]

This listing tells you that gvs3 and gvs4 are available.

In order to check the use of the GPUs on the several servers you can issue the command 

$ squeue
which gives you a listing of the running and queued requests for GPUs. 

$ squeue
JOBID PARTITION   NAME     USER        STATE       TIME TIMELIMIT  NODES NODELIST(REASON)
    249 gvs_inter   vglslurm a2815ah   PENDING       0:00  12:00:00      1 (Resources)
    228 gvs_inter   vglslurm a2815ai   RUNNING    9:03:01  12:00:00      1 gvs3
    245 gvs_inter   vglslurm a2815ah   RUNNING      30:37  12:00:00      1 gvs3
    246 gvs_inter   vglslurm a2815ah   RUNNING       0:50  12:00:00      1 gvs4
    248 gvs_inter   vglslurm a2815ah   RUNNING       0:32  12:00:00      1 gvs4
The above listing means that all 4 GPUs of gvs3 and gvs4 together are in use and the second user has already used up 9:03 hours and will be terminated when the 12 hours are used up. After that time the pending job from the first user will obtain the free GPU. It is no longer possible to make an advance reservation of a GPU in the future, because the GPUs are served: "come first serve first".

We hope that our users work in a fair way and do not block GPUs unneccessarily. In that case we would have to enforce stricter rules and limits on the use of the GPUs.