Sunday, June 6, 2010

What is your DNS speed?

I just tried the open-source DNS benchmark utility namebench. Here is the impressing result:

Google Public DNS-2 is



than your current primary DNS server

Here is a graph of the mean response duration:

The full result is at The question is: are you willing to give all your DNS queries to Google for an average of 67 ms speedup for each DNS query? Can you even feel the difference in speed?

Thursday, June 3, 2010

How to try out a new Linux distribution

Did you ever wonder how your favourite new Linux distribution looks like? Now how can you try it without installing it and ruining your current OS? All current Linux distributions allow you to boot it without installing it so that you can see how it looks and feels. I'm going to show you how you can try the new Kubuntu 10.04 LTS.

First, you have to download the ISO image from here:

Once downloaded you are going to use UNetbootin, which allows you to create a bootable Live USB drive (type "sudo apt-get install unetbootin" if it's not installed). Then type unetbootin to start UNetbootin.

Select the diskimage you just downloaded, here it's kubuntu-10.04-desktop-i386.iso. Then make sure you select the correct USB drive. Choose the type "USB Drive" and the appropriate drive. After clicking on OK it will copy the files onto the USB drive.

Once the copying is done leave the USB drive plugged in and reboot. At the BIOS you might have to select to boot from the USB drive.

Tuesday, June 1, 2010

How to extract the audio from a Youtube video?

Did you ever encounter a Youtube video you really like the audio part? I'm sure you wonder now how you can extract the audio from your favorite Youtube video. Here is how you can do it for free in three easy steps.

a) Download the Youtube video
First, you have to download the Youtube video.

b) Extract the audio from the video
You have to install mplayer (on Ubuntu: sudo apt-get install mplayer)
$ mplayer -quiet youtubeVideo.MP4 -ao pcm:fast:file=audio.wav -vc dummy -vo null -channels 2

This will extract the audio from the file youtubeVideo.MP4 and will convert it to a WAV file called audio.wav.

c) Convert the WAV file to an MP3 file
The last step is to convert the WAV file to an MP3 file which is a lot smaller and allows you to save space. For this we are using "lame" (on Ubuntu: sudo apt-get install lame):

$ lame audio.wav audio.mp3

This will take the audio.wav file and save it as audio.mp3. That's it. The file audio.mp3 contains the audio part of the Youtube video.