Intro en

Account application

To gain access to the Institutional cluster you can fill in and submit the application form.

Access the cluster and use the command line¶

The institutional cluster is accessed through a login node. Through it, input and output files are transferred and requests to perform tasks are submitted to the system that manages the resources of the cluster. Communication with the login node is done via Secure Shell (ssh).

What is ssh;

ssh is a network communication protocol that allows secure connection and transfer of data from one computer to another through encryption. The most common use is to connect a computer to a remote server.

Once the login is done you will gain access to a Linux bash terminal. If you are unfamiliar with the command line interface it would be useful to familiarize yourself with the basic file and folder management commands. The following links can help you get started:

Condition to connect with ssh to the cluster

To connect to the cluster, the computer through which the connection will be made must be on the university network. To connect from a computer located off campus (e.g. from a home network), the user must first connect to the AUTH VPN, as described here.

Once your access is activated, you can log in to the cluster with your institutional account details.

From command prompt¶

Depending on our operating system, we will use the corresponding application. - Linux or Mac OS X: Use Terminal. - Windows 10/11: Use PowerShell.

From the command prompt of your computer run the following command:

# ssh [username]@aristotle.it.auth.gr

Use the username corresponding to your account, as indicated in the account activation message for access to the service. Next, you will be asked for your ssh password.

Through Web Browser¶

You can log in via a browser with your institutional account details on the web portal of the Aristotle computational cluster. To connect with ssh to the cluster login node, you can select from the menu: Clusters -> Aristotle Shell Access as shown below:

OnDemand ssh

Using other clients¶

VS Code¶

To connect using the application Microsoft Visual Studio Code, you will need to prepare the environment using the following steps:

Now you can connect using the following steps:

To write a command to VS Code we can press the F1 key or the combination Ctrl+Shift+P, or choose from the displayed list.
By writing remote-ssh we can see different command that are available through the SSH extension.
Choose Open SSH Host... to connect.
Write in the box [username]@aristotle.it.auth.gr.
Write your password when asked.

Also, a green button appears in the bottom left corner of the VS Code. Clicking it will bring up a list of the most common SSH extension commands. Instead of steps 1 and 2, we can select the command from there.

MobaXterm¶

MobaXterm is an application that can be installed on Windows OS and has a friendly windowed interface for both ssh access and file transfer between the Windows workstation and the login node. Within the application we can work in various environments, by choosing Linux Terminal, PowerShell, cmd, git bash, etc.

MobaXterm Demo

Watch MobaXterm demo video, which presents many of its features.

Windows Subsystem for Linux

Alternatively, if we want to use Linux commands, we can use the Windows Subsystem for Linux application to connect via virtual Linux. See installation and configuration instructions.

Create a MobaXterm session

After installing the application the steps to be followed are: - Step 1: Choose new Session - Step 2: Choose SSH connection - Step 3: Fill in hostname ( aristotle.it.auth.gr ) - Step 4: Fill in username ( username of your institutional account )

First time connection¶

Host verification

Note that the first time you connect to the login node, you will probably get the following host verification message in the terminal:

The authenticity of host '***' can't be established.
ECDSA key fingerprint is SHA256: ***
Are you sure you want to continue connecting (yes/no/[fingerprint])?

Enter 'yes' from the keyboard and press 'Enter'. The fingerprint of the login node will be inserted in the known_hosts file and the next time you log in to the same host, it will not appear.

Attention! Depending on the encryption algorithm chosen by the ssh client, the fingerprint corresponding to the login nodes of the Aristotle computing cluster (aristotle.it.auth.gr) is one of the following:

SHA256:rJUQuAloAHBPTcAHK6a0cG5i3/zZwj4J2da0TJP0mk8 (ECDSA)
SHA256:XcqxZaOmf2Gtnims+wZZ5GoAX3FdsXm/vwpAzXgZOLI (ED25519)
SHA256:p2BqIbkUffvstMZw09QJ89xgeUKfcvrz5UfeIMKDT8U (RSA)