Accessing HPC resources

Setting default shell

Unix attributes are now available in the campus wide Active Directory Service and Argon makes use of those. One of those attributes is the default Unix shell. This can be set via the following tool: Set Login Shell - Conch. Most people will want the shell set to /bin/bash so that would be a good choice if you are not sure. For reference, previous generation UI HPC systems set the shell to /bin/bash for everyone, unless requested otherwise. We recommend that you check your shell setting via the Set Login Shell - Conch tool and set it as desired before logging in the first time. Note that changes to the shell setting may take up to 24 hours to become effective on Argon.

The typical way to access the HPC resources is through ssh (Secure Shell). You will need an ssh client on your laptop/workstation. If your workstation is a Linux or Mac system then you already have what you need. Simply open a terminal session and initiate an ssh session. If you have a Windows machine then you will have to obtain an ssh client. There are a couple of options but the recommended one is SecureCRT, which is licensed by the University of Iowa.

If you are on campus or connected to the University of Iowa VPN then you can access the HPC systems as follows:

on campus or off campus with VPN

 Since the standard port for ssh is often used to attempt to break into systems, an alternate port is used if you are off-campus and not connected to the VPN.

off campus without VPN

 If you are connecting from a computer where you are not logged in with your HawkID then you will have to specify the HawkID as the ssh client will try to login with the user name on the machine you are on. To do that, prepend your HawkID to the system name.

specifying username for ssh

If on a Windows machine enter the appropriate values in the configuration fields of the client application. When you receive a password prompt enter your HawkID password. If all went well you should then be logged on to the selected HPC system.

The HPC system has multiple login nodes so the above will connect you to one of the login nodes in a round-robin fashion. Generally speaking you do not have to worry about which login node you are on but be aware that different ssh sessions of yours could be running on different login nodes. The login nodes have both internal and external names with the internal name being the one visible in your shell. The mapping between internal and external names is pretty straight forward.

The above may be useful if you need to reconnect back to the same login node for some reason.