Calc

The Calc server is used for remote computing. Local user accounts are provided therefore. calc.isor.univie.ac.at can be accessed in 2 ways.

1 Functional Range

Use remote computing @calc for medium large operations. For small Operations use your laptop, for large ones Ivana's cluster. Coordinate with your colleagues, and use gkrellm to monitor system resources. (30% virtualisation-overhead might be indicated)

2 Access

2.1 Direct Access

via ssh from your client machine within VLAN-168 (with an IP: 131.130.96.Z).

2.1.1 Prerequisites

1. ssh client
2. X server

an X server is needed if graphics shall be displayed, staying in text mode you would not need it.

2.1.2 work-flow

Your console (terminal) still controls the session, so if e.g. your laptop runs short on batteries, your calculation is interrupted and lost.

• login at the remote host calc.isor.univie.ac.at

ssh -X <remote_user>@calc.isor.univie.ac.at

• make your data available
  • either by running a script to connect your lucky-data

mount_lucky <lucky_user>

• or some secure-copy transfers

scp -r <my_local_data> <remote_user>@calc.isor.univie.ac.at

• start your calculations, e.g

matlab

• transfer your outcome and delete your original data (if you don't use it any more)

or disconnect from lucky

umount_lucky

2.2 Virtual Desktop

you can use a virtual desktop to login there first, then access the calc server.

2.2.1 Prerequisites

• vnc-client like tigervnc (former tight-vnc)

yum install tigervnc or apt-get install tigervnc-viewer
or similar viewers for windows, etc.

or

• java enabled web-browser to run an unsigned applet (which normally causes troubles)

2.2.2 work-flow

Make sure to be within the university network. If working from home, establish a VPN tunnel to begin with. connecting through a virtual deskstop another username/password pair is necessary. Your username is mapped to the port:=5900+<Display> number, your password is just the same. start your vnc-client on your laptop

vncviewer 131.130.97.100:port

or - even better tunnel the session through ssh

vncviewer -via <remote-user>@calc.isor.univie.ac.at localhost:port

Best to use the Full-Screen-Mode, note the keys how to escape, e.g. <Strg> + <Alt> + <Shift> + <F> Don't forget to close the vncviewer before opening it at another host to get the geometry-settings right. Some viewers like viagre disable sending special keys by default (<Strg>+<Q> in this case). Make sure to enable them, just not to get locked out in FullScreen mode.

If you use a java-enabled web-browser and allow an unsigned applet to run, calculate your Port := 5800+<Display>

http://calc.isor.univie.ac.at:Port

Use your Virtual Linux Desktop's terminal (e.g. gnome-terminal) and continue as described in 1). Start your calculation and close the viewer. On any machine in VLAN-168 you can re-open a viewer and continue.

2.3 Applications

2.3.1 Matlab

Open a terminal via e.g. Application > Favorites > Terminal. At the command-prompt put in matlab. After the licensing server is asked for authorization the GUI starts up. Don't close this terminal, since it's the controlling terminal for Matlab. Alternatively press <Alt>+<F2> and fill in matlab. You can also use matlab in text mode from the command line.