Getting Connected

There are two ways to connect to our systems. The traditional way will require you to install some software locally on your machine, including an SSH client, SFTP client, and optionally an X Windows server. The alternative is to use our zero-client web portal, OnDemand.

OnDemand Web Portal

OnDemand is our "one stop shop" for access to our High Performance Computing resources. With OnDemand, you can upload and download files, create, edit, submit, and monitor jobs, run GUI applications, and connect via SSH, all via a web broswer, with no client software to install and configure.

You can access OnDemand by pointing a web browser to ondemand.osc.edu. Documentation is available here. Any newer version of a common web browser should be sufficient to connect.

Using Traditional Clients

Required Software

In order to use our systems, you'll need two main pieces of software: an SFTP client and an SSH client.

SFTP ("SSH File Transfer Protocol") clients allow you transfer files between your workstation and our shared filesystem in a secure manner. We recommend the following applications:

  • FileZilla: A high-performance open-source client for Windows, Linux, and OS X. A guide to using FileZilla is available here (external).
  • CyberDuck: A high quality free client for Windows and OS X.
  • sftp: The command-line utility sftp comes pre-installed on OS X and most Linux systems.

SSH ("Secure Shell") clients allow you to open a command-line-based "terminal session" with our clusters. We recommend the following options:

  • PuTTY: A simple, open-source client for Windows.
  • Secure Shell for Google Chrome: A free, HTML5-based SSH client for Google Chrome.
  • ssh: The command-line utility ssh comes pre-installed on OS X and most Linux systems.

A third, optional piece of software you might want to install is an X Windows server, which will be necessary if you want to run graphical, windowed applications like MATLAB. We recommend the following X Windows servers:

  • Xming: Xming offers a free version of their X Windows server for Microsoft Windows systems.
  • X-Win32: StarNet's X-Win32 is a commercial X Windows server for Microsoft Windows systems. They offer a free, thirty-day trial.
  • X11.app/XQuartz: X11.app, an Apple-supported version of the open-source XQuartz project, is freely available for OS X. 

In addition, for Windows users, you can use OSC Connect, which is a native windows application developed by OSC to provide a launcher for secure file transfer, VNC, terminal, and web based services, as well as preconfigured management of secure tunnel connections. See this page for more information on OSC Connect. 

Connecting via SSH

The primary way you'll interact with the OSC clusters is through the SSH terminal. See our supercomputing environments for the hostnames of our current clusters. You should not need to do anything special beyond entering the hostname.

Once you've established an SSH connection, you will be presented with some informational text about the cluster you've connected to followed by a UNIX command prompt. For a brief discussion of UNIX command prompts and what you can do with them, see the next section of this guide.

Transferring Files

To transfer files, use your preferred SFTP client to connect to:

sftp.osc.edu

You may see warning message including SSH key fingerprint. Verify that the fingerprint in the message matches one of the SSH key fingerprint listed here, then type yes.

Since process times are limited on the login nodes, trying to transfer large files directly to pitzer.osc.edu or other login nodes may terminate partway through. The sftp.osc.edu is specially configured to avoid this issue, and so we recommend it for all your file transfers.

Note: The sftp.osc.edu host is not connected to the scheduler, so you cannot submit jobs from this host. Use of this host for any purpose other than file transfer is not permitted.

Firewall Configuration 

See our Firewall and Proxy Settings page for information on how to configure your firewall to allow connection to and from OSC.

Setting up X Windows (Optional)

With an X Windows server you will be able to run graphical applications on our clusters that display on your workstation. To do this, you will need to launch your X Windows server before connecting to our systems. Then, when setting up your SSH connection, you will need to be sure to enable "X11 Forwarding".

For users of the command-line ssh client, you can do this by adding the "-X" option. For example, the below will connect to the Pitzer cluster with X11 forwarding:

$ ssh -X username@pitzer.osc.edu

If you are connecting with PuTTY, the checkbox to enable X11 forwarding can be found in the connections pane under "Connections → SSH → X11".

For other SSH clients, consult their documentation to determine how to enable X11 forwarding.

NOTE: The X-Windows protocol is not a high-performance one. Depending on your system and Internet connection, X Windows applications may run very slowly, even to the point of being unusable. If you find this to be the case and graphical applications are a necessity for your work, please contact OSC Help to discuss alternatives.
Supercomputer: 
Owens
Pitzer
Service: 
HPC