How to Control Multiple Local Computers from Ubuntu

If you've got multiple computers at your desk and would like to use one keyboard, display, and mouse setup you might want to try Synergy. This excerpt from Robin Nixon's Ubuntu: Up and Running will show you how to set it up with an Ubuntu machine.

Nowadays, with technology being so much cheaper, it’s not uncommon to have two or even more computers on your desk. The only downside is that they all require their own keyboard and mouse to operate them, which leaves little room for much else on your desk.

Luckily, there’s a very useful program called Synergy with which you can share a single keyboard and mouse across multiple computers. And, unlike using VNC, it’s a remarkably responsive system because only the mouse and keyboard data is sent across the network, rather than large amounts of graphical data.

On Ubuntu you can download and install Synergy by selecting System → Administration → Synaptic Package Manager, and entering Synergy in the “Quick search” field. This highlights two packages, synergy and quicksynergy. Mark both for installation, and then click Apply to perform the installation.

Now you must choose which computer will be your master, i.e., the one whose keyboard and mouse will control the others, and make a note of its name. For example, mine is simply called robin. Then, on each Ubuntu computer you wish to control, you should select Applications → Accessories → QuickSynergy and then click the Use tab, shown in Figure 10.13. Here, you should enter the controlling computer’s name in both fields. (The screen name just determines what name appears in the Synergy program.)

Figure 10.13. Setting a Synergy slave to use a master computer’s keyboard and mouse

Once all your slave computers have been set up, you need to configure your master. To do this, download and install both synergy and quicksynergy on that machine in the previous manner using Synaptic. But then, when you call up the program (by selecting Applications → Accessories → QuickSynergy), use the Share tab to decide where each of your remote computers (slaves) should appear, relative to your main computer’s screen. You can control up to four slaves.

So, for example, if you have two slaves, called slave1 and slave2, I would recommend placing one monitor on the left and the other to the right of your main one. Then, in the fields showing Left and Right, enter the names of the two slave computers, as shown in Figure 10.14.

Figure 10.14. Assigning slaves to the Synergy master computer

You are now ready to click the Execute button on each of your computers, and you’ll find that your main computer will allow your mouse pointer to travel all the way from the far left of the lefthand monitor, past your main monitor, and all the way through to the far edge of the righthand one. With each monitor it enters, your main computer’s mouse and keyboard will take over control of that computer.

Once you have verified that it’s all working, you can tuck the spare keyboards and mice away behind the monitors. Don’t move them too far, though, as you may need them for logging in again after a reboot, or if the master machine plays up.

If you decide you like this setup and want the convenience of having your slave computers start up automatically with each reboot, you can select System → Preferences → Startup Applications, and then enter the details shown in Figure 10.15, replacing the word master with the name of your master computer. After the next reboot you won’t need to run QuickSynergy again, although you’ll still need the keyboard and mouse to log in, unless you have chosen automatic logins. On my setup, I’ve chosen automatic logins because the slave machines are on my desk in a secure environment.

Figure 10.15. Configuring the Synergy client to run at startup

Synergy is also available for Windows and Mac OS X, but its configuration can be convoluted compared to the ease of QuickSynergy on Linux. If you would like to network Ubuntu with these types of computers, the details you need are on the program’s home page at http://synergy2.sourceforge.net. For example, using the information there, I have been able to connect a Mac, a Windows Vista and 7 computers, and some Ubuntu machines all together.

Because these are all different computers (and not several monitors connected to a single computer), you cannot drag windows or files between them, but Synergy does retain the clipboard buffer, so you can copy and paste between computers. For transferring entire files and directories between a group of computers, I usually open up a server connection, as described in the following section.