Linux stations Nymfe and Musa

Nymfe* and Musa* are student stations in the PC hall and Linux classrooms (A219, C121, C122, C123) with Ubuntu LTS OS.

During the semester, on weekdays, the stations run from 7 a.m. to 8 p.m. If someone is logged in at 8 p.m., the machine shuts down at 10 p.m. Specifically, Nymfe01, Nymfe02, Nymfe03, and Musa01 (and according to the tutorial requirements due to GPUs, also A219) run nonstop (except for the 5 p.m. reboot).

Due to limited access to the FI network, the Nymfe* and Musa* machines can only be remotely accessed from the MU network (e.g. via the Aisa machine). In addition to the usual remote access via SSH, you can also use remote access via VNC if needed.

You can also access the Windows home directory from Linux stations.

You can also read about an earlier uncharacteristic problem we had with Nymphs, or the installation of new Musa* stations in the former B011 classroom.

Room maps

The room maps in the Faculty Administration Office show the current layout and occupancy of the stations.

Troubleshooting

See Problems logging into computers (not just SSH).

Change the language of the environment

Changing the language does not work in the GNOME graphical settings, but you need to change the environment variable LANG, which is set in the .bashrc file when you create an account.

So if we want to change the language to English, we change the line:

export LANG=cs_CZ.UTF-8

export LANG=en_US.UTF-8

To apply the changes, we need to log out and log in from the graphical session.

If you are missing support for a language, let us know.

Controlling the X.Org GUI from another machine

Warning. This method only works for sessions using X.Org, and thus does not work in the new default session Ubuntu, which uses Wayland. To use x2x you must use a suitable session, e.g. Ubuntu on xorg or Plasma (X11).

Using x2x you can control another Nymfe or Musa machine from your laptop (or some Linux station) (this can be a useful alternative to free-standing monitors):

log in to the Linux station in the graphics session, which will serve as a "secondary display"
find out the name of the display via echo $DISPLAY - most often it is :0, which we will assume below
from the other machine that will serve as the primary and whose keyboard and mouse you will control the other machine, log on to Nymph (or Musa):
```
notebook$ ssh -Y xlogin@nymfeNN
xlogin@nymfeNN$ x2x -to :0 -east
```
if all goes well, the command will sort of get stuck; if you then hover the mouse over the "eastern" edge of the laptop screen, the cursor should go to the secondary screen and you should be able to control the windows with both the mouse and the laptop keyboard

You can choose other locations based on cardinal directions, but this may not always work. In particular, if you have a Unity interface on your laptop (the default for Ubuntu), -west and the most natural -north cannot be used due to the presence of Gnome Shell's bars. For XMonad or if you have problems with maximized windows, you may still need to use -struts. Copying may also be a problem - try using the middle mouse button then. (No, transitively chaining several Nymphs in a row is probably not possible.)

Container support - Podman

The Podman tool is available on the Nymfe and Musa Linux workstations. For more information, see the Aura server documentation.

Due to space constraints, clean up and delete completed containers and images when you are done!

podman system prune -a

Container data is stored in /var/tmp/containers/. Due to the higher disk space usage of containers, we do not guarantee that the data stored there will survive e.g. the whole semester.

Thanks to the podman-docker translation layer, the docker command can also be used.

GPU - A219, PC hall

Nvidia GeForce RTX 4060 Ti GPUs are available on Nymfe87-105 in A219 and Nymfe01-03 in PC Hall. Thanks to nvidia-container-toolkit they can also be used in containers (see also the GPU and Podman documentation for Aura).

In case of errors in the header files with nvcc add the gcc-12.2 module or specify -std=c++17.

Parameters

Nymphe

Intel® Core™ i5-8400 six-core (12-core) processor running at 2.8 GHz (Boost 4.0 GHz)
16 GB DDR4 RAM
500 GB NVMe SSD

Musa

Six-core (12-core) Intel® Core™ i5-11500 processor running at 2.7 GHz (Boost 4.6 GHz)
16 GB DDR4 RAM
512 GB NVMe SSD
23.8", 1920x1080 monitor

Origin of names

The names Nymphe and Muse both come from Greek mythology:

Muse - goddess of art, daughter of the supreme god Zeus and goddess of memory Mnémosyne,
Nymphs - water, forest and mountain goddesses of the Greeks and Romans, similar to our fairies and rusalka.

Vojtěch Zamarovský: Gods and heroes of ancient myths