Research IT Cluster Usage - Legacy Documentation

Documentation for using Research IT clusters on legacy Windows clients (pre Windows 10). Putty and PuttyGen were recommended ssh tools on older versions of Windows.

From Windows 10 build 1809 and later, Windows now comes pre-installed with an alternative OpenSSH.

Logging into Clusters from Trinity Network

Putty from Trinity Network - Windows Clients

This page details how to use Putty to connect to TCHPC clusters from a Windows client.

Putty is a free SSH Client for the windows platform.

  • Download the program

  • Run the application (double-click the downloaded file).

  • Enter the relevant host name from the table above

  • E.g. connecting to Kelvin with Putty putty_run_1.jpg

  • To use GUI applications (FSL,MatLab, Fluent etc), you will need to "Enable X11 Forwarding". putty_x11_forwarding_0.jpg

  • For GUI application, you will also need XMing.

  • Click the 'Open' button to launch your Putty session. You will see a window similar to the following. putty_run_2.jpg

  • Enter your username and password and then press enter to login.

  • Note: The password prompt will not echo back your password characters when you type in your password. This is a standard security feature. Please enter you password as normal and press enter.

Logging into Clusters from Outside the Trinity Network

To login from outside the Trinity Network you must first create an ssh keypair for your local machine. This consists of a private key which will remain on your local machine, and a public key which will be copied to the host machine (eg rsync.tchpc.tcd.ie).

Generating SSH Keys for Logging in - Windows Clients

(Instructions sourced from here).

Windows 10 and later comes pre-installed with OpenSSH which can be used from Windows PowerShell. It is recommended to try the method using PowerShell first. Else, download and install PuTTYgen.

Create New Public and Private Keys

If you have not yet created an ssh keypair follow these instructions. If you already generated an ssh keypair, skip to convert ssh key to putty format.

  1. Launch PuTTYgen.
  2. Under Parameters, increase the Number of bits in a generated key: to a minimum value of 4096.
  3. Under Actions / Generate a public/private key pair, click Generate.
  4. You will be instructed to move the mouse cursor around within the PuTTY Key Generator window as a randomizer to generate the private key.
  5. Once the key information appears, click Save private key under Actions / Save the generated key.
  6. Save the private key to the desktop as id_rsa.ppk.
  7. The box under Key / Public key for pasting into OpenSSH authorized_keys file: contains the public key.
  8. Jump to copy the public key to rsync.

E.g.

putty_key_generator_key.png

Convert SSH Key to Putty Format

If you already generated an ssh keypair using a tool other than Puttygen, you may have to convert your private key to the puttygen .ppk format in order to use with Putty.

  1. Launch PuTTYgen.
  2. In upper toolbar, click Conversions > Import key

puttygen_conversion.png

  1. Navigate to and select your private key (eg C:\Users\your_username\.ssh\id_rsa)

puttygen_privatekey.png

  1. Enter your key passphrase if prompted.

  2. Click Save private key.

puttygen_savekey.png

  1. Save in C:\Users\your_username\.ssh with filename id_rsa.ppk

Copy the public key to rsync

Follow these instructions if you are on the Trinity network. If you are not on the Trinity network, email your public key to ops@tchpc.tcd.ie.

The public key is located in the box under Key / Public key for pasting info OpenSSH authorized_keys file:. The public key begins with ssh-rsa followed by a string of characters.

  1. Highlight entire public key within the PuTTY Key Generator and copy the text. (Note: You may have to scroll down to view the entire key, be careful here!)

  2. Launch PuTTY and log into rsync.tchpc.tcd.ie with your existing credentials.

  3. Use your preferred text editor to create and/or open the authorized_keys file:

nano ~/.ssh/authorized_keys
  1. Paste the public key into the authorized_keys file.
ssh-rsa AAAAB3N... == rsa-key-mine

  1. Save the file and close the text editor.

  2. Adjust the permissions of the authorized_keys file so that the file does not allow group writable permissions.

chmod 600 ~/.ssh/authorized_keys

Using PuTTY to login with an SSH key pair ####

If you have already configured PuTTy before and have working saved sessions, please skip to step 8. If this doesn't work, then restart from step 1.

  1. Open the PuTTY application.

  2. Enter rsync.tchpc.tcd.ie under Session.

putty-rsync-tchpc-tcd-ie.png

  1. Go to Connection > Data. Enter your username under Auto-login username.

putty-username.png

  1. Go to Connection > SSH > Auth. Click Browse... under Authentication parameters / Private key file for authentication.

putty-key.png

  1. Enter directory at top of search bar, replacing your username with your pc username C:\Users\your_username\.ssh and click enter. Double click on file id_rsa.ppk or id_rsa to open.

putty-private_key_location.png

  1. You should now see your private key path in Putty. Retry step 5 if not visible.

putty-private_key_confirm.png

  1. Go to Session. Enter a suitable session_name under Saved Sessions and click Save to save session configuration.

putty-save_session.png

  1. Double-click on your new session_name in the second box below Saved Sessions to launch.

putty-launch.png

  1. If configured correctly you should see a screen asking for your ssh passphrase or your password.

putty-launch_screen.png

  1. Enter your password or ssh passphrase when prompted.

Note: The password prompt will not echo back your password characters when you type in your password. This is a standard security feature. Please enter you password as normal and press enter.

putty_ssh_auth.png

Once logged into rsync, then log into the HPC cluster you wish to access, e.g. Kelvin, with the following command:

ssh -X kelvin.tchpc.tcd.ie

See the table above for the list of HPC Clusters if you need to login to another one.