Necessary account information

Before trying to log in to any of the C3SE systems you need to be equipped with the following:

  • Your username, called Chalmers ID (CID)
  • Your password, called CDKS password, (CDKS == Chalmers Datorkontosystem)
  • An account on each C3SE system you are going to use (i.e. Hebbe or Vera). Everyone has to apply for an account, even if you already have a CID

If you lack any of this, please read the instructions on how to get access.

Required software

Our systems all run some type of Unix environment and the main interaction with the systems is performed using a command-line interface (CLI). If you do not have any previous experience of a Unix command-line interface here are two guides that will get you up to speed: Introduction to Linux and GNU/Linux Command-Line Tools Summary.

To connect to the cluster and the aforementioned command-line interface you need a terminal (emulator) and an implementation of the Secure Shell (SSH) protocol. For Windows users we recommend using the free program PuTTY that is a terminal emulator with SSH built in. Unix users (including Linux and Mac OS X) can use the terminal emulator and SSH that is shipped with the operating system.

Hostnames and network access

To connect to C3SE resources the Secure Shell (SSH) protocol is used. Every cluster has a so called "Login Node" that is accessible from the internal network on Chalmers University of Technology, and follow the hostname convention: or or # Only accessible for MStud users

If you are connected to the Chalmers local network you can login directly by running:


where you have to replace CID with your CID username and cluster with the name of the cluster frontend you want to connect to, eg. hebbe1, hebbe2, hebbe-mstud, vera1, vera2.

If you are not directly connected to the Chalmers local network, you have two options:

  • Use the Chalmers Virtual Private Network (VPN) service to first connect to the Chalmers local network. With an active VPN connection to Chalmers it is then possible to log in using SSH to the cluster "Login Node". If you are a student you will find instructions here: VPN for students

  • Use SSH to first connect to one of the Chalmers ssh-remote servers where X is a number in the range 1-2. After logging in to one of these machines using SSH you can use SSH a second time to log in to the cluster "Login Node"

Note: For Hebbe we allow direct access (i.e. no VPN or ssh-jumping necessary) from universities connected to Sunet.

Graphical login

Instead of connecting through a terminal, you can also access to the cluster through Thinlinc which gives you a graphical connection.

Logging in through Chalmers ssh-remote servers

Open a terminal window on your local computer and log in to one of the Chalmers SSH remote servers (replace the username emilia with your CID user name). Available servers are: and

$ ssh
The authenticity of host ' (' can't be established.
RSA key fingerprint is SHA256:DTkLJVG9V/vV7bsZvKgd7+Psz8CCittHOWf52TVRhho.
Are you sure you want to continue connecting (yes/no)? yes

If this is the first time you connect to the remote server you might get this warning. In this case there is no need to worry, answer yes to continue.

Warning: Permanently added ',' (RSA) to the list of known hosts.'s password:

To log in input your CDKS password. If you get the message Permission denied, please try again, double check that you've read and input your CDKS password correctly and try again. If you still fail after a repeated number of attempts please raise a support ticket by contacting C3SE support.

Now the computer is directly connected to the internal Chalmers network so from this computer you can directly connect to the C3SE clusters using SSH.

$ ssh's password:
Last login: Thu Feb 31 12:34:56 1988 from
Welcome to Hebbe
[emilia@hebbe2 ~]$

Congratulations! You are now connected to the login node of a cluster computer that packs at least 1000 times more computing power than your desktop computer. Let's figure out how to wield this power.

Setting up a hostname alias

Optionally, you can (on your local machine) set up alias by modifying the file


and add an entry e.g:

Host hebbe2
    User your_cid

Host vera1
    User your_cid

# etc.

This will allow you to conveniently scp/ssh to the cluster doing

ssh hebbe2            # This would now be equal to: ssh
scp my_file hebbe2:   # This would now be equal to: scp my_file

Setting up ssh key

From MAC and Linux you can generate an SSH-key, upload it, and use this to log into the system, e.g:

ssh-keygen -t rsa
scp ~/.ssh/ hebbe2:.ssh/authorized_keys

SSH is picky about the file permissions on both ends, else it will refuse to use the keys. You'll have to log into the cluster and modify using chmod:

chmod go-rwx .ssh/ .ssh/authorized_keys

The SSH-key can also be used by all applications connecting to the cluster, such as FileZilla or Thinlinc. You can set up your computer to unlock the key by putting it in a keychain.