Frequently Asked Questions (FAQ)

Q: Is it possible to add another Interactive App to the list of available OnDemand apps?

A: Email to request this and we will look into it. Until then, you can run the "Desktop" app, load the modules you need, and launch the app yourself from within the "Desktop" app.

Q: When I start my application the resolution is very low. How can I make it better?

A: You can go into "My Interactive Sessions" and adjust the "Compression" and "Image Quality" sliders for your session to try to improve the resolution.

Q: Is there a way to extend the time limit for an OnDemand app/session I currently have running?

A: No, there is no way to do this.

Q: Can I add my own custom app?

A: No. The "Interactive Apps" menu is set by the SCC system administrators. If you have a suggestion for an application that should be added please e-mail

Q: When I start my app in OnDemand, I can not see the menu for my application and I can't see the title bar in order to move the window. What should I do?

A: On the Mac, pressing "Alt-F7" (Alt is also the "Option" button on the Mac) may enable you to move the window; in our testing this works by default under Firefox but under Chrome requires prior installation of the Caret Browsing extension.

On Windows, you can also press "Alt-F7" (Alt is also the "Option" button on the Mac) to allow you to move a window. This will likely ask you a question about "Caret Browsing". Say yes to this question and then move the window so that you can access the menus. Click once in the window after you have the window positioned as you want.

Alternatively, on Windows, at the top of the browser window there should be a grey bar that says "Applications" on the left. You can find the tab for your application in this bar, right click, and select "Move" to move the selected window.

Q: I am using a phone or other small browser screen. I can not see any of the navigation tabs mentioned at SCC OnDemand Help. What is going on?

A: With a small screen, SCC OnDemand replaces the direct tab links with a hamburger button. If you click on this, it will allow you to access all of the same content.

Q: I have a quota warning message displayed in my OnDemand session. Can I still start OnDemand sessions using this project?

A: Yes, generally. If your home directory is completely full (100%), you may not be able to run "Interactive Apps". You would still be able to use the "Files" tab to delete files and use the "Login Nodes" tab to open a shell and clean things up that way. Any directory being 100% full may of course cause problems if your applications are trying to write files to that directory.

Quota warnings are displayed for your home directory and all Project Disk Space directories you have access to that are at least 95% full.

Q: How do I Copy & Paste from within OnDemand?

A: If you are working within a "Login Nodes" shell or a "Servers" session from "Interactive Apps", cutting and pasting should behave normally.

However, if you are working in a "Desktops" app (Desktop, MATLAB, Mathematica, etc...) cutting and pasting is more involved.

Q: Why does the URL for OnDemand show scc-ondemand1 or scc-ondemand2?

A: There are two OnDemand nodes and users are automatically redirected to one of or You can also go directly to these URLs. Interactive sessions are shared so if you end up in one case on scc-ondemand1 and launch a session, you will still be able to access it later if you connect to scc-ondemand2 and vice-versa.

Q: How do I change the default keyboard shortcuts (e.g. copy/paste) in the SCC OnDemand Desktop?

A: Some users may find it useful to change the Linux keyboard shortcuts, such as changing copy from CTRL+SHIFT+C to CTRL+C. In order do to this, edit the file ~/.config/xfce4/terminal/accels.scm. For example, to change the keyboard shortcut for copy, change the line:

 ; (gtk_accel_path "<Actions>/terminal-window/copy" "<Primary><Shift>c")


; (gtk_accel_path "<Actions>/terminal-window/copy" "<Primary>c")

Note: These keyboard shortcuts are ONLY for use inside the Linux Desktop on SCC OnDemand. Changing these shortcuts will NOT change the copy/paste behavior between your local computer and SCC OnDemand.

Q: Duo is not working for me to access SCC OnDemand even though I know I set it up. What can I do?

A: The problem may be an incompatibility between some extension that you have installed for your web browser and Duo. We have seen this happen with Chrome and believe it could happen with other browsers. We suggest disabling all of your browser extensions and seeing if Duo then works. In Chrome, go to the three vertical dots at the top right, Settings, then Extensions on the left side. Disable any extensions in the list, then close the browser, reopen, and try to log in to SCC OnDemand again (or BUworks as if this is the issue it would also apply there). If it works with all extensions disabled, you can then turn each one on one-by-one and narrow down which one is causing the issue. This web pages also has instructions for disabling and removing extensions in Chrome.

Q: Can I use SCC OnDemand if I have just a Linux Virtual Lab/scc-lite account?

A: Yes, but you can not do some things. For example, your interactive applications are limited to a single processor, no GPUs, and a duration of 12 hours. You also only have access to your home directory to store files.

Q: How can I check my connection speed to the SCC?

A: You can go to our speedtest website to measure the speed of your connection to the SCC. In addition and for comparison, you can conduct a free internet speed test at any test provider, for example or In such way, you can compare your regular internet speeds with the speed of connection with the SCC. You can consult our page on Home Internet Connectivity for more information.