Setting up the first time (Windows)

You will need the program MobaXterm which will help you with the following tasks

  • Logging in to the databar.

  • Displaying the ASE graphical user interface on your laptop.

  • Forward a connection to the Jupyter server (SSH tunnel).

  • Accessing files on the remote server from your laptop.

Installing MobaXterm

You download the program from the website https://mobaxterm.mobatek.net. Choose Download, select then “Free Home Edition”. You are now given a choice between a “Portable Edition” and an “Installer Edition”. The Installer Edition is installed like any other Windows program; the Portable Edition comes as a ZIP file that you need to unpack. The program is then in a folder together with a data file, and you can run it from this folder. We have tested the installer version, but assume that both work.

You must unpack the downloaded ZIP file before you run the installer, running it from inside the ZIP does not work!

Configuring your secret key

For security reasons, all access to DTU computers require two-factor authentication. In the case of the HPC installation, the two factors are your password and an encryption key (SSH key). You get your secret SSH key by connecting to https://www.student.dtu.dk/~dccidmgr/CAMD24/ then add your user name to the end of the URL and press enter (Guest accounts only, DTU users please do this instead). You will now be asked to authenticate with username and password, when you have done that right-click on the link to save the file. Save it on your laptop.

Start MobaXterm. You will see a window with a row of buttons at the top. Click on the Settings button (one of the last ones). On the configuration window that opens (shown below) you select the SSH tab. The last box is labeled “SSH agents”, select “Use internal SSH agent MobAgent”.

Click the Plus sign next to the box labeled “Load the following keys at MobAgent startup” and then select the file with your private SSH key. You have to select “All files” in the file type menu to see it. The file name will be your user name, perhaps with .txt added. Then press OK; MobaXterm will then need to restart.

../../_images/MobaXtermKeyConfiguration.png

Connecting the first time

Start MobaXterm. You will see a window with a row of buttons at the top. Click on the Session button, you will now see a window as shown below.

../../_images/Moba_ssh.png

In the tab Basic SSH settings you should choose Remote host to be login.gbar.dtu.dk. Click the “specify user name” checkbox. The user name is your DTU user name (external participants got it in the registration material). The port number must remain 22. Click OK and give your DTU password in the text window when prompted. NOTE Nothing is written when you type the password, not even stars.

We do not recommend allowing MobaXterm to remember your password!

You now have a command-line window on the DTU login-computer, as shown below.

../../_images/Logged_in_Win.png

The two last lines are the command prompt. The first line indicates your current working directory, in this case your home folder symbolized by the ~ (tilde) character. The lower line gives the name of the computer (gbarlogin) and the user name (jasc in the figure) followed by a dollar sign.

This computer (gbarlogin) may not be used for calculations, as it would be overloaded. You therefore need to log in to the least loaded interactive computer by writing the command:

linuxsh -X

(the last X is a capital X, you get no error message if you type it wrong, but the ASE graphical user interface will not work).

Get access to the software

To get access to the software you need for this course, please run the command:

source ~jasc/setup2024

Note the tilde in the beginning of the second word.

The script will install ASE, GPAW and related software. The script will also copy a selection of draft notebooks to a folder called CAMD2024 in your DTU databar account.

Carrying on

Now read the guide for Starting and accessing a Jupyter Notebook