start:mogon_cluster:access

Accessing MOGON

Essentially only accounts of the Johannes Gutenberg University can get access.

  • External users can approach us to retrieve more information concerning so-called guest accounts.
  • Internal groups with external members should approach their person in charge of accounts at the deanery of your faculty or at the secretariat of the respective institution.

Remote Access

Since the MOGON clusters are Linux-based systems, remote access is granted via SSH.

To access MOGON refer to these instructions: access MOGON using Linux/macOS / access MOGON using Windows. The latter link contains information for accessing MOGON with PuTTY, MobaXterm and PowerShell.

Login to the login-nodes is mediated by a jump node: Access is done with direct login (ssh) to "mogon". This name implements a Round-Robin-DNS login to both login nodes of MOGON I, mil01.zdv.uni-mainz.de and mil02.zdv.uni-mainz.de. If for some reason you want to login to a specific login node, you can use these names directly. (or if for some other reason one of the nodes is broken, and the DNS always gives you the wrong, broken one to connect to)

The login nodes of MOGON II are miil01.zdv.uni-mainz.de to miil03.zdv.uni-mainz.de. Projects on MOGON I do not have access to MOGON II automatically. You have to apply for MOGON I and MOGON II separately.

Login

Only password-less login is available.

MOGON Service Nodes Overiew

Service Node FQDN Cluster Description
login21 miil01.zdv.uni-mainz.de MOGON II Login Node
login22 miil02.zdv.uni-mainz.de MOGON II Login Node
login23 miil03.zdv.uni-mainz.de MOGON II Login Node
login01 mil01.zdv.uni-mainz.de MOGON I Login Node
login02 mil02.zdv.uni-mainz.de MOGON I Login Node
hpcgate hpcgate.zdv.uni-mainz.de MOGON Jump Host

SSH-Key

You need to have your SSH-Key uploaded on account.uni-mainz.de/sshkey to be able to log in to MOGON1).

Your SSH-Key is automatically added to the MOGON clusters. Would You Like To Know More? Read this Article!

SSH-Keys for MOGON require certain information in the comment of the SSH-Key that describes the purpose of the Key. The information is catched by a script and ensures that you can access MOGON correctly.

MOGON SSH-Key comment additions

Make sure you add the following strings to your SSH-Key as part of your comment, to specify the purpose:
Purpose Comment String related to MOGON Access
Using the jump host hpcgate HPCGATE
Log in to MOGON service nodes HPCLOGIN

In case you not yet have an SSH-Key pair on your computer, you can use the following command to create a new pair:

ssh-keygen -t rsa -b 4096 -C "HPCGATE,HPCLOGIN"

This generates a new private/public RSA key pair with 4096 bit key size.
Please note: The part -C “HPCGATE,HPCLOGIN” creates the mandatory comment, which can be pasted into the web form.
Then ssh-keygen asks for a name for the key.

Enter a file in which to save the key (/home/you/.ssh/id_rsa): [Press enter] 

After that you have to specify a passphrase - Do not use an empty passphrase!

Enter passphrase (empty for no passphrase): [Type a passphrase]
Enter same passphrase again: [Type passphrase again] 

In this case you deviate from the default names and you ought make your ssh-agent aware of it:

ssh-add ~/Path/To/Your/PrivateKey

Modify existing SSH-Keys

If you already have an SSH-Key pair, you can change the comment as follows, for example to add the HPCGATE,HPCLOGIN string if you have forgotten to append it:

ssh-keygen -c -C "HPCGATE,HPCLOGIN" -f ~/Path/To/Your/PrivateKey

Set up SSH-Keys for MOGON using Windows

We have created an article for you here that explains various ways to create new SSH-Keys using Windows, including PuTTY, MobaXterm and PowerShell.

1)
A neat overview on ssh-keys and how to generate and copy them can be found here. Or you can follow our guideline
  • start/mogon_cluster/access.txt
  • Last modified: 2020/08/06 17:04
  • by jrutte02