The Center for High-Performance Computing (CHPC)

The Center for High-Performance Computing is the single most important resource for the Clark group. Within this shared computational environment, we perform chemical simulations/calculations on collections of powerful computers, storing the resulting data on robust servers. Accessing this resource may initially seem intimidating. This page will hopefully demonstrate how simply a connection to CHPC can be established, as well as give readers a set of useful tools to start navigating and creating.

This page expands upon the CHPC's personal page for getting started accessing shared resources with some additional Clark Group-specific tips. Additional help can be found online or on the CHPC's homepage.

Making an Account

All University of Utah students/faculty who wish to access CHPC must first set up an account. This account is tied to your university login and provides a simple and integrated way to access all the resources the CHPC provides:

• IT helpdesk for personal incidents/questions

• User/group usage and storage analytics

• Real-time system status updates

• Computing tutorials (past content and upcoming virtual lessons)

• Open OnDemand, a browser-based way to access CHPC

To make an account, fill out the online account request form here.

Connecting to CHPC

Researchers in the Clark Group access CHPC resources via one of several networking interfaces, which help establish a connection (session) between your personal computer (the client computer or client node) and CHPC (the server computer or server node) via wi-fi or Ethernet. The number of interface options available to choose from can be overwhelming; however, at their core, each one is simply a way for users to pass commands and files back and forth from their personal computers (nodes) to the shared nodes in CHPC.  The following sections will advise on several different interfaces that are commonly used in the Clark Group and demonstrate how to use these interfaces to connect to CHPC.

Choosing an Interface

Below are several interface options for connecting to CHPC, how to set them up, and some of their pros and cons.

Connecting to a Server: Basics

All of the interfaces provided will use the same protocol when establishing a connection to CHPC. This method is called the SSH (secure shell) protocol. SSH is a standard for connecting to remote computers, which allows data to be transferred securely between your personal computer and CHPC, no matter which interface you decide to use. The general command to establish this connection is:

ssh username@hostname

Which is entered directly into your computer's command line. For CHPC connections this command is:

ssh uXXXXXXX@chpc_host_name.chpc.utah.edu

Where uXXXXXXX is your 7 digit university ID preceeded by 'u', and 'chpc_host_name' is the keyword for the collection (cluster) of computing nodes you want to connect to. See the next section for tips on choosing a cluster. 

Choosing a Cluster

This decision will be motivated by the type of work you plan on doing and which clusters are currently active, but for Clark Group members, the choice generally comes down to one of two types.

Computing Clusters: These clusters consist of a Head Node and Compute Nodes. The head node meets the user when you first log in and is available to tackle day-to-day manual tasks such as copying/moving files and running small scripts. These tasks and any others that involve direct user keyboard input are called 'interactive'. The head node is powerful but is used concurrently by many users; therefore, to avoid causing network traffic, larger tasks are submitted to compute nodes, which dedicate private resources to your computing alone. 

• Notchpeak (hostname- notchpeak.chpc.utah.edu)

• Kingspeak (hostname- kingspeak.chpc.utah.edu)

• Granite (hostname- granite.chpc.utah.edu)

• Lonepeak (hostname- lonepeak.chpc.utah.edu)

Interactive Clusters: These clusters are beefier than the head nodes of computing clusters and are available for longer or more computationally expensive interactive commands.

• Frisco (hostname- frisco.chpc.utah.edu)

And Finally ... Connecting

Once you've set-up your CHPC interface of choice and know which cluster you want to connect to, you can proceed to connecting to CHPC.

Local Command Line

1. Open your computer's command-line / terminal (see setup above)

2. Enter the OS-specific SSH command

   • Windows: Enter 'ssh uXXXXXXX@chpc_host_name.chpc.utah.edu' , replacing 'uXXXXXXX' with your uID and  'chpc_host_name' with the cluster name you would like to connect to (e.g. ssh uXXXXXXX@notchpeak.chpc.utah.edu)

   • Mac: Enter 'ssh -X -Y uXXXXXXX@chpc_host_name.chpc.utah.edu' , replacing 'uXXXXXXX' with your uID and  'chpc_host_name' with the cluster name you would like to connect to (e.g. ssh -X -Y uXXXXXXX@notchpeak.chpc.utah.edu)

3. Enter your password

4. Enter '1' to send a Duo 2-factor authentication push notification (for info on setting up Duo go here)

5. Using your phone or laptop confirm the Duo push notification to login

6. To exit a session type 'exit' and click enter

Note for Windows users: Windows does not have a built-in X server for X forwarding CHPC graphics windows. This means that you will have to download a 3rd party X forwarding server to see graphics displayed by CHPC. Alternatively, you may use MobaXterm, which has a built-in X server.

Open OnDemand

1. Go to https://ondemand.chpc.utah.edu

2. Log in with your username and password

3. From the dashboard click 'Interactive Desktop'

4. Select the cluster you would like to connect to from the drop-down down

5. Select the account and partition you would like access under from the drop-down down

6. Select the number of CPUs (cores) you would like to use from the drop-down down

7. Select the number of hours you would like your session to be active for from the drop-down down

8. Click 'Launch'

9. Once session goes from 'Queued' to 'Running' click 'Launch Interactive Desktop'

10. Enter your password and click enter

11. To exit a session type 'exit' and hit enter or close the tab. Your session will be preserved on your dashboard until its time limit expires.

FastX (Browser version)

1. Open up a session in a web browser by going to http://servername.chpc.utah.edu:3300 (replacing servername with one of the CHPC cluster names).  

2. Sign in using your University of Utah uNID and associated password

3. To start a new session with a terminal and X forwarding click on the 'xterm' play button, this will open a new tab with an active terminal

4. To disconnect a session, go back to your dashbaord tab, click the three dots on the session, and choose disconnect (or close the session tab). This will disconnect you from CHPC and save your session on your dashboard for you to come back to later

5. To reconnect to an existing session, login to the same server, and click on a given session and hit the play button. Again the session will open in a new browser tab.

6. To permanently delete a session. Go to your dashboard tab, click the three dots on the session, and select terminate.

7. To log off you go to the pull down menu associated with your username near the top right of your web browser window and select "Sign Out".

Note: Once you have a terminal tab open, near the top of the web browser window there are a few icons - these include an online keyboard, a file manager, and settings. If you choose one of the desktops, there is also an icon to resize to full screen.

For tips on downloading and using the desktop version of fastX go here.

MobaXterm

1. Open MobaXterm

2. Select 'New session' from the session drop-down

3. Select the SSH option

4. Under 'Remote host' enter chpc_host_name.chpc.utah.edu' , replacing  'chpc_host_name' with the cluster name you would like to connect to

5. Click the 'specify username' box and enter your uID (uXXXXXXX replacing 'uXXXXXXX' with your uID)

6. Enter your password (if you haven't saved a password)

7. Enter '1' to send a Duo 2-factor authentication push notification (for info on setting up Duo go here)

8. Using your phone or laptop confirm the Duo push notification to login

9. To exit a session type 'exit' and click enter

Sharing Resources on CHPC