1. How do I connect to sand using VNC?
You can connect to a graphical session on sand from any computer on campus. There are two versions of VNC (Virtual Network Computer) on the campus image, RealVNC and TightVNC. The are almost interchangeable, except for a few keyboard features and the way graphics are handled. Most people find RealVNC slightly more polished.
1.1. Using a web browser
You can connect to a VNC session from modern web browsers (no other software required) using one of the links:
https://sand.truman.edu/vnc/ (this redirects to the direct link https://sand.truman.edu:6900/vnc.html)
Watch a video showing the connection process at YouTube.
1.2. Getting VNC
For Windows, RealVNC and TightVNC are free downloads. For Mac, Chicken of the VNC is a free download. For Ubuntu Linux and similar, both are available through the package manager:
$ sudo apt-get install xvnc4viewer xtightvncviewer1.3. Getting Remmina
Even more convenient than RealVNC or TightVNC, Linux users will probably prefer Remmina, which uses VNC but over a secure link. This means that they can use it from on or off campus to access sand.
$ sudo apt-get install remmina1.4. Connecting to sand
Sand has VNC servers running at different resolutions on different "display numbers".
VNC sessions are available at resolutions 800x600, 1024x768, 1280x1024, 1280x800, and 1600x900. Each resolution is available on its own "port number" starting from port :0 up to :4 (or starting from :10 up to :14 for TightVNC).
For use in the classroom, 1280x1024 is the native resolution of the student workstations. Connect to sand:2 if you want to work full screen with VNC from a student workstation. The newer wide screen projectors in our classrooms have native resolutions of 1280x800, so a full screen VNC session on the projector should connect to sand:3.
:0 or :1 or :2 or :3 or :4 RealVNC version 4
:10 or :11 or :12 or :13 or :13 Tight VNC
:20 or :21 or :22 RealVNC version 4 (low color)For example to get a display window size of 1024x768, using RealVNC, you would want to connect to sand.truman.edu:1.
1.5. Connecting from off campus
VNC traffic will not pass through the Truman firewall. If you want to use VNC from off campus, the simplest way to do that is to use VPN software. There are downloads and directions at https://secure.truman.edu/its-s/vpn/.
Linux users may choose to use openconnect to connect to the VPN or to create an ssh tunnel manually instead (display ports start at 5900 for display :0, 5901 for :1, and so on). For example:
$ ssh -f -L 5901:localhost:5901 sand.truman.edu sleep 10
$ xvnc4viewer localhost:1An alternative solution for Linux users is to simply run the Remmina Remote Desktop Client. Remmina can automatically wrap your VNC sessions in an encrypted SSH tunnel (check the box under the SSH tab). This will give you both security and a way to penetrate the Truman firewall.
2. How do I connect to sand using X2Go?
An alternative to VNC is X2Go which is based on the same underlying technology that made NxClient popular. There are clients available for Windows, MacOS, and Linux from http://wiki.x2go.org/doku.php/download:start For most Linux users, it will be packaged and can be installed directly by command:
$ sudo apt-get install x2goclientSession types currently supported by sand are: xfce4, kde, and wmaker. To get a wmaker session, you’ll have to define a custome session with the start command wmaker.
3. What do I do if X2Go suddenly broke for me?
Sometimes a session of X2Go can get "stuck." You can minimize the probability of that occuring by logging out of your sessions when finished, but that still isn’t 100%. So you need a way to restore things to normal.
When you can no longer connect via X2Go, you need another way onto sand to kill the remaining broken parts of your session. You can use Putty to login to a text interface, or use VNC to get a graphical login.
Once you’re on sand again, type this command in a terminal to kill all of your processes:
$ kill -9 -1If you wait about 60 seconds, X2Go should work for you again.
4. How do I connect to sand using Xpra?
Xpra is available from the Programs menu on the student image. I prefer to create a shortcut on my Y: drive with all of the options that the program needs. To do this, open you Y: drive and the Programs menu then right-drag the Xpra icon onto your Y: drive to create a shortcut.
Once you have created a shortcut, right click it and changed the Properties. You want to edit the Target property to:
"\\ss1\Viewdata\ThinApp\20192020\Xpra 2.5.1_fy19v2\Xpra.exe" start ssh/%USERNAME%@sand.truman.edu --pulseaudio=no --exit-with-children --speaker=disabled --microphone=disabled --start-child=konsoleSave the changes. Then to access sand, double click on the shortcut. You’ll be asked for your Truman password, and after a short delay a Konsole terminal window will appear. You may start any other programs from there by typing their command name on the command line.
5. The tab key doesn’t work when I use VNC and xfce4
This seems to be a confusion between the Tab key and Super-Tab. It can be fixed by typing this command:
$ fix-keysIt isn’t important for you to know, but the actual command that fixes the keybinding is:
xfconf-query -c xfce4-keyboard-shortcuts -p /xfwm4/custom/'<'Super'>'Tab -r6. I can’t resize windows in xfce4
This is an issue with the default theme. You can resize windows from the corners, but the side decoration is so thin that it is difficult or impossible to grab on. There are various short-cut ways to resize, but I’ve personally found it simpler to switch to the Kokodi theme.
Select the menu option Applications Menu/Settings/Window Manager and choose your theme on the Style tab.
7. How do I copy file to or from sand?
Perhaps the easiest way to copy files to or from sand is using magic-wormhole, which is already installed on sand. It is already packaged for most Linux systems, so if you are running Linux on your personal machine, you can easily install it.
It is available in MacPorts for MacOS computers. If you’re using Windows, then a Windows binary is available here:
On one machine you use wormhole to send a file or folder (which will also send all the files contained in the folder):
$ wormhole send hello.txt
Sending 17 Bytes file named 'hello.txt'
Wormhole code is: 7-sympathy-deckhand
On the other computer, please run:
wormhole receive 7-sympathy-deckhandUse the random code provided by magic-wormhole on the receiving machine to accept the file.
Y:> wormhole receive 7-sympathy-deckhand
Receiving file (17 Bytes) into: hello.txt
ok? (y/N): y
Receiving (->tcp:150.243.163.159:32847)..
100%|██████████████████████████████████████████| 17.0/17.0 [00:00<00:00, 396B/s]
Received file written to hello.txtYou can see a video of the process at: https://youtu.be/nOyysKvcXs4
8. How do I access my Y: drive from sand?
8.1. Graphical method
If you have logged in graphically to sand (using VNC or NxClient) then you can use one of the graphical file managers to access your Y: drive. The file manager under Gnome is nautilus. The file manager under Xfce4 is thunar. The file manager under KDE is dolphin.
The file managers can browse files over the network if given an appropriate smb: URL address. At Truman, our Y: drives are stored on a server named hydrogen under our user names. For example, to browse the files for the user dbindner, the address would be smb://hydrogen/dbindner.
If you can’t find a location box to type in the address (in nautilus or dolphin) hit Ctrl-L to make it appear.
You can see a video of the process at: https://youtu.be/4lll3mD8KZk
8.2. Command line method
The smbclient utility can access your Y: drive to get and put files, much as we old-timers used to access FTP sites. It can be told to get your cached password automatically with the -k flag.
$ smbclient -k //hydrogen/dbindner
...9. How do I print from sand?
Student printing at Truman is managed by a piece of software called PCounter. Sand is configured with a printer named pcounter that prints to these printers. You can select it from the the printer dialog window when printing from graphical programs, and you can also indicate it from the command line.
$ lpr -P pcounter file.ps
|
You will need your password to print a job, even from the command line. The prompt from the printing system is a popup dialog, so to my knowledge it is not possible to print to PCounter from a text-only session (like ssh). |
You can also submit files/jobs via their web interface at:
As of February 2018 there is an issue with the security key at that site, so you may have to add an exception to your web browser to use it.
10. How do I start a videoconference?
Sand has Jitsi videoconferencing software installed, and it should be suitable for small groups to use, especially when all parties are on the campus network (because no traffic needs to leave the fast local ethernet). Anyone with a valid Truman username and password can start a meeting room.