[Spring-2021] getting VNC to work on CCH

[Borries Demeler]

You should all have access to our server in Lethbridge now, and be set
up with a VNC connection. In case you have difficulty getting  your
connection re-established, here are a few steps that should get you back
connected (confirmed to work by Jimmy):

The basic approach for getting VNC to start again would be this:

On your computer:
1. open a terminal (Mac/Linux) or cmd.exe (Windows 10)
2. ssh username at cch.uleth.ca

On demeler9/cch:
3. sudo vncctl restart
4. exit (from cch)

On your computer:
5. ssh -fN -C -L 5901:localhost:59NN username at cch.uleth.ca
6. restart vncviewer locally and make a connection to 127.0.0.1:1 or localhost:1

A few notes:

1. You need to change 'username' to your account name
2. You need to change 'NN' to your VNC display number
3. On Windows, you need to change '-fN' to just '-N' (-f puts your ssh
session into the background, but the Windows version is too dumb to do
it, and just locks your terminal, to exit this session you can just 
close the window or ctrl-C to stop)
4. On Mac, the realvnc client seems to work, but may need some settings
adjusted such as the color depth - try 16- or 24-bit colors
5. On step 3 (restarting your VNC server) the program will also remind
you of your display number. You can run it anytime, it may die when we
reboot the server or need to do some maintenance on the server (rare,
just when we upgrade the kernel).

Voila, you are running on a remote Linux server!

Good luck! -Borries