Originally Posted by mvernia
When they come up in Linux mode, the PCs are not connected to a central server.
You mean not connected to a LAN at all?
Or not part of a Windows domain?
I would like to impress my students with the multi-user capabilities of Unix (Linux). How can I run multiple users on a single PC?
At my work we have several shared Windows machines that are used by one person at a time from their own Windows or Linux workstation using some form of either VNC or Remote Desktop (we use a few different forms). It is inconvenient, because before grabbing a system with VNC or Remote Desktop you can, at most, tell whether someone else is logged in. You can't tell whether they are actually doing something or even if they are still connected (vs. just forgot to log out when they disconnected).
We also use several Linux systems via various forms of putty, ssh, X windows servers, or VNC. Since Linux is inherently multi user, there is no conflict except for CPU time and ram, which you can check with top
before launching a big job.
So depending on how you have things networked, and on what other Linux or Windows workstations you have handy when you want to demonstrate "multi user", you might want to use one of those methods to remotely log into a Linux system while someone else uses it directly. All of X windows, VNC, ssh, and maybe putty are easier to install and use on a Linux workstation to access another Linux system on your LAN than to install on Windows for use in accessing Linux. But all of them can
be installed on Windows for Linux access. Most people here use Windows workstations to access the Linux systems.
Students may not understand the value of using one computer as a terminal to use another computer. So any impressiveness of Linux multi user may be diluted by the need for each user to tie up a full computer to get access.
A multi seat single Linux system would get the point across in a more impressive way. But it is much harder to set up. You obviously need a second of each of monitor, keyboard and mouse. I don't know how much harder it is with one dual head display interface. I think using a second display interface instead of one dual head is generally recommend. Even then the software setup for dual use can be tricky. Also IIUC, if you have both keyboards or both mice USB (vs. one PS2 and one USB), the identity of the keyboards or mice tends to get swapped on reboot.
I'm hoping soon to install SGE (Sun Grid Engine) to distribute work across several Linux systems (rather than have individuals use top to find out which systems are lightly loaded enough for the task they want to run). That might make a more impressive demonstration for you than either remote log in or multi seat. But I think you would need to first switch all the Linux systems to some form of shared authentication of users (we already have that here). Once you have properly configured SGE, I think you could demonstrate tasks submitted to SGE automatically running (as the original submitting user) on whichever of the Linux systems is lightly loaded, even if that Linux system has someone else logged in (assuming they aren't using a lot of CPU time).