Texas Tech University

Connecting to HPCC Systems

The HPCC currently operates three primary clusters RedRaider, Quanah and Ivy. RedRaider will be merged with Quanah shortly, and the Ivy system will be converted to in interactive resource, but for now these can be accessed separately. These all run the CentOS Linux operating system, but can be accessed from any client using the appropriate tools. Instructions for how to connect to our HPCC  clusters depends on the operating system you are using as a client and whether you are attempting to sign in from within or from outside the TTU campus network. Instructions for each of these dependencies can be found below.

Table of Contents:

  1. Logging in to the HPCC Clusters using Windows
    1. Getting an SSH client
    2. Connecting to HPCC Resources via SSH on Windows
  2. Logging in to the Linux Clusters using Linux/Mac
    1. Connecting from "On Campus" using Linux/Mac
    2. Connecting from "Off Campus" using Linux/Mac

Logging in to the HPCC Clusters using Windows

If you are connecting to the HPCC Linux clusters from the wired TTU network or the TTUnet wireless network, or if you are connected from off-campus through the TTU Global Protect VPN client, then you are considered to be "on campus". Connections made from TTUHSC, the TTUguest wireless network or any other off campus site not in this list are treated as "off campus". For off-campus connections, follow the procedures outlined below and then navigate to the off-campus instructions for the SSH gateway at the end of this page.

Getting an SSH client

For users to connect to the HPCC Linux cluster systems they need a Secure Shell (SSH) client. Windows provides an SSH client through its PowerShell window or Command Prompt windows but most Windows users prefer to use one of the following SSH Windows applications. Other available options for plain-text terminals include Termius, which is available for macOS, Windows, Linux, iOS and Android.

  • Plain-text-only terminal applications:
    • Windows Subsystem for Linux (WSL) - Available on Windows 10 only
    • PuTTY - Available for all version of Windows
      • PuTTY is a lightweight SSH client developed by Simon Tatham.
      • PuTTY can be downloaded (for free) from the PuTTY Website.
  • X11 graphics-enabled applications:
    • MobaXterm is an enhanced terminal application for Windows with X11 server, tabbed SSH client, network tools and more. If you are needing to display X applications from the HPCC system, MobaXterm makes it easier since it does not require additional programs to provide X11 forwarding.

Connecting to HPCC Resources via SSH on Windows

Once you have obtained and installed a suitable SSH client on Windows, please follow the instructions below to make a connection:

  • Windows Subsystem for Linux (WSL) - Available on Windows 10 only
    • Because this method will install a lightweight version of Linux on your system, you can continue connecting to our Linux clusters using the "Logging in to the Linux Clusters using Linux/Mac" section below, which includes sections on connecting from on campus and from off campus.
  • PuTTY - Available for all version of Windows
  • MobaXterm has an extensive help page showing how to connect, including how to set up port forwarding in a way similar to PuTTY for off-campus connections. In general, these are similar to the instructions below.

Logging in to the Linux Clusters using Linux/Mac

If you are connecting to the Linux clusters from the wired TTU network or the TTUnet wireless network, or if you are connected from off-campus through the TTU Global Protect VPN client, then you are considered to be "on campus". Connections made from TTUHSC, the TTUguest wireless network or any other off campus site not in this list are treated as "off campus". For off-campus connections, follow the procedures outlined below and then navigate to the off-campus instructions for the SSH gateway at the end of this page.

On Macs, the built-in Terminal application can be used for plain-text connections, and XQuartz is the best option for X11 graphics-enabled usage. Linux systems generally include a terminal application and options to install X.org X11 support for graphics-enabled applications. When using X11, be sure to add the "-X" flag to the ssh commands given below to enable X11 forwarding.

Other available options for plain-text terminals include Termius, which is available for macOS, Windows, Linux, iOS and Android.

Connecting from "On Campus" using Linux/Mac

Open a new console/terminal and type in the following:

#Connecting to RedRaider
ssh <eraider>@login.hpcc.ttu.edu
#Connecting to Quanah
ssh <eraider>@quanah.hpcc.ttu.edu
#Connecting to the Ivy login node
ssh <eraider>@ivy.hpcc.ttu.edu

You will be prompted for your eraider password and once you have entered it you will be logged into the cluster where you can begin submitting jobs.

Connecting from "Off Campus" using Linux/Mac, WSL, or other terminal applications:

If you are connecting to the Linux clusters from the wired TTU network or the TTUnet wireless network, or if you are connected from off-campus through the TTU Global Protect VPN client, then you are considered to be "on campus". Connections made from TTUHSC, the TTUguest wireless network or any other off campus site not in this list are treated as "off campus". All external traffic to the HPCC servers must first flow through the SSH gateway. You will first need to connect to the SSH gateway and then connect to Quanah or Hrothgar from there. To do this you will need to first open a new console/terminal and type in the following:

#Connect to the TTU SSH Gateway
ssh <eraider>@ssh.ttu.edu

You will be prompted for your eraider password, type it in then press enter. Once you have successfully entered your eraider password, the system will respond back with:

You are now connected to the TTUnet SSH Gateway. 
Please specify the following information to continue
connecting via SSH to a device on the network.
This connection will automatically timeout in 24 hours
Hostname or IP Address of SSH instance:
#Enter either login.hpcc.ttu.edu, quanah.hpcc.ttu.edu
#or ivy.hpcc.ttu.edu
User account to connect with:
#Enter your eraider username

You will be prompted for your eraider password and once you have entered it you will be logged into the respective login node where you can begin submitting jobs.

If you wish to connect in just one command line through the ssh gateway, please follow the instructions below. The format of this command depends on which version of SSL you are using.

With OpenSSH (used in Linux, Mac, and optionally installable in WSL), you can use the "-J" (jump) flag, as below:

#Connecting to RedRaider off-site through TTU SSH gateway using OpenSSH
ssh -J <eraider>@ssh.ttu.edu <eraider>@login.hpcc.ttu.edu
#Connecting to Quanah off-site through TTU SSH gateway using OpenSSH
ssh -J <eraider>@ssh.ttu.edu <eraider>@quanah.hpcc.ttu.edu
#Connecting to Ivy off-site through TTU SSH gateway using OpenSSH
ssh -J <eraider>@ssh.ttu.edu> <eraider>@ivy.hpcc.ttu.edu

If your setup is using other older versions of SSH, such as built into PuTTY or the current default WSL, connecting in one line from off-site requires the following set of flags:

#Connecting to RedRaider off-site through TTU SSH gateway 
#other SSH versions
ssh -o ProxyCommand="ssh -W %h:%p <eraider>@ssh.ttu.edu" <eraider>@login.hpcc.ttu.edu
#Connecting to Quanah off-site through TTU SSH gateway 
#other SSH versions
ssh -o ProxyCommand="ssh -W %h:%p <eraider>@ssh.ttu.edu" <eraider>@quanah.hpcc.ttu.edu
#Connecting to Ivy off-site through TTU SSH gateway 
#other SSH versions
ssh -o ProxyCommand="ssh -W %h:%p <eraider>@ssh.ttu.edu" <eraider>@ivy.hpcc.ttu.edu

In each case, you will have to enter your eRaider password twice (once for the SSH gateway and once for the cluster login node).

GUI-based SSH applications such as MobaXterm and Termius, include options to allow port forwarding to be set up to use the TTU SSH gateway for off-campus connections. For instructions on how to configure such settings, please consult the help instructions in the web sites for these programs.

 

High Performance Computing Center