One keyboard and mouse for multiple computers running Ubuntu

When you have multiple computers on your desk, it can be very annoying to switch keyboard an mouse each time you want to do something on one of the other computers.
So, you can solve this by just using one keyboard and one mouse for multiple computers without buying a hardware switch.
Synergy is a package, available from the repository that lets you share the mouse and keyboard over a range of different computers.
When synergy is active, your keystrokes will be send to the machine where your cursor is currently positioned.
The cursor will slide from screen to screen just as if you are working on one single system with multiple screens attached.
As far as I know, it’s not possible to drag windows from one machine to another. Which would be nice.
So if you’re a programmer and you’re still searching for a useful project, then this is just your bit.

Here is how you can easily start sharing your keyboard and mouse between different computers and screens using synergy on Ubuntu:

First off, install the synergy package and the QuickSynergy packages on each machine you want to use your pointer on with the command:

sudo apt-get install quicksynergy

Note that apt will install the synergy package as it’s required to run QuickSynergy. (QuickSynergy is in fact just a gui for Synergy)
When it’s installed, you’ll find QuickSynergy under the category ‘accessories’ in the application menu.

On the server:

The server is the computer where the used keyboard and mouse are attached to.
In the Share tab fill in the names of the computers where you want your keyboard and mouse to be operational.
Do not fill in the IP address, it won’t work.

Synergy server

To find out the name of your computer(s), open a terminal and type:


If all the hostnames are put in the right place, start the service by clicking ‘Execute’
Note that the window becomes gray.
You can now just minimize it and let it do it’s work.

On the client:

On the Client, fire up the QuickSynergy app and go to the Use tab.
Fill in the hostname of the server.
Note that you can also enter its IP, but know that when you’re using dynamic IP adresses, you’ll have to reconfigure this each time you fire up Synergy.

Synergy Client

Then just hit execute and minimize the window.
Now you can remove your keyboard and mouse from this computer.

When moving the mouse outside the window to the side you’ve configured the other computers position on the server, you’ll see your pointer go ‘troug’ the space between the two computers and appear on the other screen.
Als handy to know is that the clipboard is shared.
So you can actually copy something on machine 1 and paste it on machine 2. (text that is, don’t try this with data)

Synergy uses an unencrypted TCP/IP stream on port 24800. So if you’re on a network you can’t entirely trust, don’t use it unless you encrypt it.
I would even recommend ALL users using a wifi-network to encrypt the connection.
To Encrypt the Synergy data, you can simply follow the guide on their website.

Ubuntu Server on VirtualBox returns error This kernel requires the following features not present on the cpu: 0:6

I installed Ubuntu Server 8.04 inside a VirtualBox (v 2.4.1_OSE) virtual machine.
The installation went smooth, but when I wanted to boot into my Ubuntu Server, it returned the following error right after GRUB:

This kernel requires the following features not present on the cpu: 0:6
Unable to boot – please use a kernel appropriate for your CPU

Screenshot or it didn’t happen?

Ubuntu Server on VirtualBox returns error

How to solve:

This can be easily resolved by enabling the PAE/NX option in the virtual machine’s settings.
This will expose the PAE of your CPU to the virtual machine.


  1. go to the homescreen of Virtualbox
  2. select your virtual machine
  3. click the ‘settings’ button on top of the screen
  4. click the tab ‘Advanced’
  5. check the box next to ‘PAE/NX’

Like in this screenshot:

Screenshot-testserver - Settings-1

Now, you can fire up your virtual machine again, and it will start up without this error.

Tips: GRUB

GrubGRUB is one of the most common used bootloader on linux.
So, when using linux, and you’re a bit interesting in ‘what’s under the hood’,  it’s the first thing you want to learn about.

When you turn on your computer, the bios will start the bootstrap procedure from the primary boot-device.
(If you’re planning to run a LiveCD, you might make that your CD/DVD-rom drive) 😉
A bootstrap is in fact nothing else than having a small program, so that this can load a bigger one.
That’s the thing GRUB does, in short!
What you should remember, is that it’s important, and you would not like to break it.
If you do, you’ll render your hardisk unbootable.

So the first thing you want to do, is back up your MBR!
Why not just GRUB?
The MBR is a 512-byte segment, the first sector, on your harddisk.
GRUB takes 446 bytes, the partition table takes 66 bytes
and the 2 remaining bytes are for a signature.
You might want to keep these 3 intact.

Continue reading Tips: GRUB

Keypad not working in Ubuntu 9.04

numkeyjpgAfter I installed Ubuntu 9.04 (Jaunty) I noted that my keypad didn’t work anymore.
I never searched to fix this bug as I’m not using it that often. (The top-row number are far more efficient to use)
My first laptop (dell latitude d820) made me learn how to work without the numeric part. Afterwards, this was not such a bad thing. Typing without using the keypad makes typing much quicker. You should give it a try some day!

But now my girlfriend wanted to use my computer to do some internet banking, which uses quite a lot of numeric digits to get authorized, and thus I have to fix it.
It seems like this is a problem in
This bug has already been registered on Launchpad with the number #197589.
The quick work around is disabling the “Pointer can be controlled using the keypad”-option in your keyboard settings.
Or just disable it by hitting “Ctrl + Alt + Num Lock”
There, that solved the problem… not that hard, but handy to know 😉

Weird requests on the website

I was looking at the stats for and I was a bit surprised to see these easy attempts to compromise data from the website.
There were several 404 errors returned on files with names such as:

  • /packet.mdb
  • /
  • /shop.rar
  • /
  • /site.rar
  • /web.rar
  • /
  • /
  • /www.rar
  • /tomdb.mdb
  • /shop.mdb
  • /shoes.rar
  • /wwwroot.rar
  • /HSH.mdb
  • /
  • /HYTop.mdb

Continue reading Weird requests on the website

Running a virtual machine on Ubuntu 9.04

Ever wanted to test something on another platform than the current one you’re on?
Needed to take screenshots of a windows environment  while having a *nix-only network?
Then you might consider running the extra OS as a guest in a virtual machine.

There are lots of different ways to do this on Ubuntu.
You might want to use VMware, Xen, KVM, Iguest, rhyp, UML, qemu, OpenVZ, … catch my drift? 😉 Continue reading Running a virtual machine on Ubuntu 9.04