Virtualbox update to 3.2 – A error occurred during the signature verification

In Ubuntu machine I have installed Virtualbox with Windows so I can run software for Windows. Last time I tried to upgrade the machine using the apt package manager of Ubuntu (sudo apt-get update) I got the following error:

A error occurred during the signature verification. The repository is not updated and the previous index files will be used.GPG error: http://download.virtualbox.org karmic Release: Οι παρακάτω υπογραφές ήταν μη έγκυρες: BADSIG 54422A4B98AB5139 Oracle Corporation (VirtualBox archive signing key)

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How to delete certain files using find and piping them to rm in linux

If you need to delete many files with same characteristics like the same name or the same extension then you can use the find command and then rm to remove them.

So here is what I did:

find /home/ -name "*xml.gz" -print0 | xargs -0 rm

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Ubuntu Proftpd very slow: how to speed up

I have installed proftpd in my Ubuntu. When I was downloading it was slow enough to make me searching for some answers… Well I found some. Here they are:

#UseReverseDNS — Toggle rDNS lookups UseReverseDNS off
#IdentLookups — Toggle ident lookups IdentLookups off

Placing these lines at your /etc/proftpd/proftpd.conf you will get more speed at your file transfers.

How to add sound to your videos using mencoder

If you need to add some sound to your videos and you are using Linux, there is a very easy way to add it.
You can for example add your favourite song into your video, or even record your voice and put it in your video.

mencoder source.avi -o destination.avi -ovc copy -oac copy -audiofile /path_to_the_mp3_file/file.mp3

By telling mencoder not to compress the source video nor the audio the hole procedure will take a few seconds.

Enjoy it !!!

Ubuntu – An Easy linux distribution

Update (27 June 2016): The Free CD ordering is no longer working, but you still can download Ubuntu and make your own bootable DVD/USB drive.

A friend of my friend asked if there was a linux distribution (distro) that is easy to use, to learn without any complicated installations and configurations.

My friend you are very lucky. Yes there is ! Try Ubuntu Linux. There isn’t more simple installation (as far as I know) as Ubuntu’s. It’s free, easy to use and if you have an adsl line you can download more software. But there is more !

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