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. (don't be afraid of 30% virtualisations-overhead - we may later buy another server to split virtualisation from computing)

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

connecting through a virtual deskstop another username/password pair is necessary. Your username is mapped to the <Display> number, your password is just the same. start your vnc-client on your laptop

vncviewer 131.130.97.100:<Display>

or - even better tunnel the session through ssh

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

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.