How to: Synergy & Linux (Debian and Ubuntu) & Mac OS X

Synergy is an application that provides a software KVM over the network. This means that you can use one keyboard and to control several computers mouse over a network.

I am using it from a Debian Linux machine to control an Ubuntu netbook and soon a MacBook (3 computers, 3 different operating systems, 4 screens, but only 1 keyboard and mouse needed).

The software is cross platform and works in Unix/Mac OS X/Windows. The Windows version has a GUI and is not dealt with in this How To as none of it is related. I will get around to write a How To on that one when I get a Windows PC back on my network, which may take a few more months.

You can use any server and any client to communicate to each other. Therefore, you can use a Windows machine to control both Linux and OS X machines.

Important security note: Synergy is not encrypted so keyboard entries can be sniffed over the network. So do not use this software over public networks and if you have to, use a VPN with encryption to protect your passwords.

Instructions

You need to use the terminal for this How To.

To install on OS X, I assume you download the package and copy it to a folder of your choice. You then work out of that folder. I will have to experiment with this (expect an update).

For both Debian and Ubuntu, you need to first add the package by using apt-get (or Synaptic). I prefer apt-get cause its quicker than Synaptic (low end machines and I spend a good amount of time in terminal).

To get it, you enter this command into the terminal (assuming it is in your repository list, it was already in mine).
(sudo***) apt-get install synergy
***Omit "sudo" for Debian: you need to be a superuser/root. So either log in as root or type su to log into a superuser account.

For the server machine:
Create a file called "synergy.conf" in your /home folder (you can use cd ~/ to get to it)
Copy the following text to it (default setup for 2 screens).

section:
$screens
$screen1:
$screen2:
end section:
links
$screen1:
right = $screen2
$screen2: left = $screen1
end

Replace $screen1 with your server's IP or hostname.
Replace $screen2 with your client's IP or hostname.
This assumes the left screen is the server, otherwise, reverse my instructions.

This is just an example setup, you can add as many monitors/PCs and their relative positions from each other. There are tons of options you can configure to suit your exact needs.

Start the server by using the command: synergys -f --config synergy.conf

(-f is for debugging purposes. Once everything works, you can remove it and it will run in the background. Use ctrl-c to kill the application when in debugging mode)

To start the client

To connect to the Synergy server, enter the following command on the other machine: synergyc -f server-host-name

Replace server-host-name with your server's hostname or IP address. I use the IP address method. (Again, -f is for debugging purposes, you should remove it once everything works).

If everything works, you won't see an error messages. Try to move your mouse from screen/PC to the other and everything should work.

Autostarting

To autostart it, you can make a shell script that runs at startup with the above command. Synergy has a few tips on where and how to do this. I've been experimenting with putting them into the /etc/init.d/ directory but that didn't work for me (an unrelated script dissapeared on next boot. Have to investigate why.) As long as it gets the job done, no single way is the right way.

Reference: Synergy's guide.

[I will try to upload pictures later]