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FastX2, from StarNet, is a utility that can be used to interact with remote linux systems graphically in much more efficient and effective way than simple X forwarding. A FastX2 interactive session can be disconnected from without closing the session, allowing users to leave applications running and resume their sessions from other locations. More information on this utility can be found on the StarNet website:

A short training video walks through the installation and usage of the FastX2 desktop client and supplements this page.

CHPC's StarNet license allows for multiple FastX2 server installations; We recommend using the cluster interactive nodes (or the frisco peak nodes frisco1- frisco8) for this service, however if you have a demonstrated need for this to be installed on a CHPC supported system please contact CHPC.  If there are compatibility complications with the FastX2 server, one may need to use a different window manager than your preferred one, e.g., using XFCE instead of gnome.

Update - 09 Jan 2018

You can once again dowload the fastX desktop cleint via the web interface.  See the installation section below for details.

What's New with FastX2

  1. You no longer need to provide license information with the use of FastX2 client. All licensing is at the server side.
  2. FastX2  has a web based client which you can access entering the server name appended with ":3000" in the web browser, e.g.,  While this is not meant to replace the heavy client, users may find it convenient.   The desktop client, which can be installed with the directions given below, still offers better performance for demanding applications. Details of how to use both the web based and the desktop client are given below. 
  3. With the desktop client, there is no longer a need or a mechanism to disconnect from the server; but users can still suspend, terminate, and resume sessions.


The lastest clients are avaiable via the web client.  Go to one of the CHPC interactive nodes via the web client (see instructions below).  Once you log in, on the bottom right-hand side of the window, there is a "Desktop Client" link. From there, you will see download links for the client version which match the current server version for Mac, Linux, and Windows desktops.

The licensing also allows for multiple FastX server installations; please contact CHPC if you are interested in an installation of the server on CHPC supported resources.

CHPC has the FastX2 server installed on all cluster interactive nodes, as well as a set of nodes allocated specifically for FastX use. These nodes are the friscopeaks nodes. They can be accessed by ssh,  through the FastX interface via friscoX.chpc.utah,edu, where X is 1 through 8, or via the FastX2 web client as described above. All of the frisco nodes have graphics cards to enable the use of VirtualGL for accelerated graphics. See step 9 of the 'To Use' section below for further instruction on the use of VirtualGL.

If you have any issues with FastX2, please contact User Services at

Note: if you have an existing FastX client installation, all of your server definitions will be moved over when you do the installation of the FastX2 client.

CHPC Usage Policy

  1. Users should by default use the frisco resources for FastX usage.
  2. The CHPC usage policy for the general interactive nodes still applies when using FastX. See Policy 2.1.1. When in doubt about the computational requirements of a workflow, it is better to use one of the frisco nodes or a private owner interactive node.
  3. When using FastX, users should connect directly to a specific resource. The generic pattern "" is not the name of a single server, but a round-robin address which does not guarantee a connection to a specific interactive node. Users will need to explicitly select the address of the desired node. For ember, kingspeak, and telluride, this will be or (for example, kingspeak1 is; for ash-guest, this is or Frisco peaks are through
  4. CHPC may establish additional usage policies for FastX2 depending on evolving user needs and usage patterns.

Using the Web Client

  1. Open up a session in a web browser by going to (replacing servername with one of the CHPC servers, e.g., kingspeak1, notchpeak1)
  2. Click on Start a new Session (or open up an existing one) and type in the command to start the session
  3. Once you have a terminal, near the bottom of the web browser window there is an icon with a few options.  Note that cut and paste between this FastX2 session and a window outside of this session does not work well.  
  4. To keep a session active, you can go to the tab with your sessions listed, and click on the session you want to keep and hit the pause icon. You can then log off.
  5. To reconnect, login to the same server, and click on a given session and hit the play button.
  6. To log off you go to the pull down menu near the top right of your web browser window.

Using the Desktop Client

  1. Start the FastX client on your desktop (Note: If you are connecting using a VPN, be sure to start the VPN prior to opening the FastX client.)
  2. Use the "+" found in the upper right corner to define a server. You need to provide a name, the host and a user (your unid) data. As an example, you can use the host and name it frisco1. Leave the port set as 22. Do not change the entry on Sci and leave the FIPS compliant mode unchecked. 
    • Servers can be edited (clicking on the right "pencil") or deleted by clicking on the X-icon on the right edge.
    • You can create several several entries (i.e. different hosts & names)
  3. Once you have one or more servers defined you can select one of them and login by clicking on them. When you do so, two windows will open. In the top window you will be asked to enter your password (linked to your unid) . As soon as you are logged, the password window will disappear and the main window will appear (its title contains the server's name and host from step 2.)
  4. To open a new session on this server, click on the "+" symbol in the top window.
  5. A new window will pop up. You need to either take one of the options given in the window or add a command. When you do this the session becomes defined in this window, along with the start and last connect time, and a new window opens for your session. Your choice depends on your needs.  There are both full desktop (Gnome, KDE, and XFCE, Mate desktops) and different xterm/terminal options .
  6. If you want to finish the session, you can close this window.  Please do this for any session that you are done with to ensure there are sufficient resources available to meet the active user needs. 
  7. If you want to keep the session in order to return to it, right click on the session name in the list and select the pause ("||"  button)  You can close the FastX window listing the sessions at this point, and this closes your connection on the server.
  8. To reconnect, either from the same desktop or another, start FastX2, select and login to the same server, and you should see your saved session. Right click on the session, and select the "play" buttion. All windows you had open when you disconnected will appear.
  9. For applications that need or can benefit (better performance) from the use of virtualgl: All the frisco nodes have a graphics card. You must start the application with virtualgl.  For example for starting vmd you would use "vglrun -c proxy vmd". Note that in the case that your application call is a script, as is the case with using gv to start gaussview, this will not work; instead you need to add this vglrun internal to the script.
  10. Please be sure to close any sessions you no longer need to keep the number of sessions at a minimum.


    1. For users of Gaussview who are not using modules you will need to source /uufs/ before starting Gaussview with gv. With the use of modules you would do a module load gaussian09 (unless loaded via the custom.csh script.
    2. For users of the CSDS program mercury, you will need to use VirtualGL for the molecules to appear in the display window.

    3. To cut/paste to or from the FastX window: see We advise MAC Users to NOT use the regular XTerm terminal but to opt for either the Mate Terminal or KDE Terminal. In the latter terminals, the copy command is <CRTL><SHIFT>c ; the paste command is <CRTL><SHIFT>p (The <CTRL> c command is an interrupt in Linux/Mac).
      The copy and paste "commands" are also visible under the "Edit Button".
    4. For users of Abaqus, you must use the -mesa flag (abaqus cae -mesa) or your model will not display.
    5. If you are connecting to a node with a graphics card (this applies to all of the frisco nodes) from a Linux or an OSX machine using ssh -X, add -c proxy flag to the vglrun command, that is, vglrun -c proxy vmd. This forces the VirtualGL to use the X11 transport.


FastX Troubleshooting

1) Make sure to close your fastx client (on the machine your working on), re-open the fastx application and try again. When the network (your client IP address) is changed out from underneath your host, the fastx client needs to be restarted.

2) Verify that you can ssh to the host your attempting to fastx to, if you can't ssh then fastx will not work. You can also try to use the web fastx version by pointing your browser to If neither of these work for you, then there's a high probability that the desktop version of fastx will not work.

If you can't even ssh then it could be the destination host doesn't allow ssh from where (the network or IP) your coming from.
This could be from a number of reasons, some listed below.
     a) Could be the host you are trying to ssh to requires you to have a UofU IP.  If that is the case then connect to the UofU vpn first then try again. is the UofU entry point for VPN.
     b) It could also be that your coming from a network or IP that is blocked (temp or permanently) from the campus border - if you suspect this then you can ask CHPC by sending email to
     c) Your ssh client could be misconfigured, make sure you have your client configured for ssh v2.
     d) Make sure DNS is working on your host (both forward and reverse lookups), this means you can open up a terminal or command line and type 'nslookup and have it return and IP # (, then type 'nslookup' and it should return the name of
If this doesn't work you may have a name service resolution problem on your client. You can fix it or you can just use the ip # instead of the name.

3) Make sure you have the latest FastX, you may need the new one - to get the new one or compare the one you have with the new one.
     a) To find the version # that your running (go to fastX and click on 'help' > 'about')
     b) To download and install the new client. You can go to and click on "Looking for the desktop client?"

4) You may need to delete the sessions files in you CHPC home directory and try again.. (with %hostname% being the one that's having issues)
in your CHPC home directory, do (by 1st ssh'ing to a host which mounts your CHPC home directory such as
     cd .fastx_server/%hostname%/sessions
     rm -rf C-*
OR you can just remove or rename the entire .fastx_server/%hostname%

     a) If things are still not working... Does fastx to that server work from a different fastx client (if you have this on another client to test).
Please send email to with with the version of fastx your using, the operating system your using (linux/osx/windows, etc), the host IP your working on (e.g., one way to get this is to visit and tell us what "your IP" says, and other error messages and information is helpful including if you've successfully done this before and this is a new problem or if this is your 1st time.

5) Make sure you don't have any alternative Python environment loading at the login via the shell init scripts (.custom.[sh,csh], .tcshrc, .bashrc). Some Python modules that CHPC provides, such as anaconda3, break FastX login. If you need Python, load the module after the FastX connection has been established.

Documentation from StarNet, the maker of FastX2 is at


Last Updated: 9/4/19