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Login via a terminal

Learning outcomes

  • Practice using the documentation of your HPC center
  • Understand what a console environment is
  • Understand what a terminal is
  • Understand what a prompt is
  • Understand that after login, one is on a login node
  • If needed: has installed an SSH client
    • Windows: MobaXTerm
  • Can log in to the console environment using a terminal
For teachers

Teaching goals are:

  • Learners have practiced using the documentation of their HPC cluster
  • Learners understand what a console environment is
  • Learners understand what a terminal is
  • Learners understand what a prompt is
  • Learners understand that after login, one is on a login node
  • If needed, learners have installed an SSH client
    • Windows: MobaXTerm
  • Learners have logged in to the console environment using a terminal

Teaching non-goals are:

  • Use X forwarding

Prior questions:

  • What is a console environment?
  • What is a terminal?
  • What is a prompt?
  • What is SSH?
  • What is an SSH client?
  • Do you know any SSH clients?
  • What is a login node?
  • How to behave on a login node?

Feedback questions:

  • Q: What is a console environment?
    • A: a text-only environment
  • Q: What is a terminal?
    • A: the text-only program to work with your computer
  • Q: What is a prompt?
    • A: the text before the place where you type
  • Q: What is the purpose of a prompt?
    • A: it shows, among others, in which folder you are
  • Q: What is SSH?
    • A: a protocol to transfer files
  • Q: What is an SSH client?
    • A: the program to transfer files via SSH with
  • Q: What is a login node?
    • A: the first computer of your HPC cluster you arrive at
  • Q: How to behave on a login node?
    • A: only do light calculations

Why?

Using a terminal is powerful, where a remote desktop is clumsy. Copy-pasting text to a terminal on the remote desktop will quickly make you wonder if it cannot be done in a smarter way.

But, this is already in the prerequisites???

Yes, we indeed require you to have done this in the prerequisites.

The goal of this sessions (see 'Learning outcomes' above) is to gain more understanding about what you've already done.

A terminal and SSH clients

A terminal is a text-only program that can do many things, for example, starting a program. An SSH client is a program that allows you to connect to another computer. Some SSH clients can run from a terminal or vice versa.

Exercises

Need a video?

The solution of these exercises can be found in the FAQ 'How can I login to an HPC cluster?'

How difficult will this be?

This depends mostly your operating system and HPC cluster:

Operating system Difficulty Reason
Linux Easy Pre-installed and working SSH agent
MacOS Hard Access rights clash with SSH agent
Windows Medium Need to install MobaXterm
HPC Cluster Difficulty Reason
Alvis Hard Uses SSH keys, must be in SUNET
Berzelius Easy Uses password
Bianca Medium Uses password, must be in SUNET
COSMOS Easy Uses password
Dardel Medium Uses SSH keys
Kebnekaise Easy Uses password
LUMI Medium Uses SSH keys
Rackham Easy Uses password
Tetralith Easy Uses password
Vera Easy Uses password

Here, we log in to your HPC cluster's console environment via a terminal.

Exercise 1: a terminal

Go to the documentation of your HPC center, then answer these questions:

  • Find the page on terminals, if any
I cannot find it. Where is it?

If it is absent, use your favorite search engine instead.

  • What is a prompt?
Answer

The prompt is the text at the start of the line you can type on. It indicates that the terminal is waiting for user input.

Exercise 2: install an SSH client if needed

Go to the documentation of your HPC center, then answer these questions:

  • Find the page on SSH clients
Answer

If it is absent, use your favorite search engine instead.

  • Try starting a terminal and type ssh and then enter. If you do not get an error message, you are lucky to have an SSH client installed!
How does it look like when ssh works?

Your output will look similar to this:

richel@richel-N141CU:~$ ssh
usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface] [-b bind_address]
           [-c cipher_spec] [-D [bind_address:]port] [-E log_file]
           [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file]
           [-J destination] [-L address] [-l login_name] [-m mac_spec]
           [-O ctl_cmd] [-o option] [-P tag] [-p port] [-R address]
           [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]
           destination [command [argument ...]]
       ssh [-Q query_option]
  • If there is an error, install the recommended SSH client

Exercise 3: login via SSH

Go to the documentation of your HPC center, then answer these questions:

  • Find the page about how to login to your HPC cluster via SSH and a password
I cannot find it. Where is it?
  • Log in to your HPC cluster
How does that look like?

For UPPMAX's Rackham, your output will look similar to this:

sven@richel-N141CU:~/GitHubs/uppmax_intro_day_1/docs/sessions$ ssh -X sven@rackham.uppmax.uu.se
sven@rackham.uppmax.uu.se's password:
Last login: Thu Aug  8 18:35:17 2024 from vpnpool189-229.anst.uu.se
 _   _ ____  ____  __  __    _    __  __
| | | |  _ \|  _ \|  \/  |  / \   \ \/ /   | System:    rackham1
| | | | |_) | |_) | |\/| | / _ \   \  /    | User:      sven
| |_| |  __/|  __/| |  | |/ ___ \  /  \    |
 \___/|_|   |_|   |_|  |_/_/   \_\/_/\_\   |

###############################################################################

        User Guides: https://docs.uppmax.uu.se/

        Write to support@uppmax.uu.se, if you have questions or comments.


[sven@rackham1 ~]$

Welcome on a login node!