Cleaning out linux-image-x.x.xx-xx-* files

I was suddenly denied access to my in-house web-server with a message telling me the disk is full. After a quick check with df -h I could confirm the root partition used 100%.
First I started to look for "user -files" I could remove, but found out there wasn't all that many of them. Most of the usage was in the folders /lib, /usr and /var. A quick question to my friend google took me in the direction that there could be some linux-image files no longer used that were spending my disk.
Some more searching gave me the following solution to removing these unused kernel files:

Formatting phone numbers in LibreOffice

Every now and then I need to setup a list containing phone numbers in Libre Office Calc. When the phone numbers are listed I need to have them formatted in 3+2+3 digits. (Or else I'm unable to separate the digits when I am going to make the call.)

Here's the trick how to do this:
In the phone number column I'll select the entire column or the cells I need the formatting on.
Right click the selected area and click Format Cells
In the Numbers tab, I insert the following as Format Code:

###" "##" "###

Make sure to add the space between the " and ".

Correctly inserted phone numbers should now look like: 123 45 789
(A lot better for my ageing eyes.)


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Using netcat as a server

Just this morning I was checking out some piece of software and was trying to setup its mail configuration. But it would not function the way I thought it was supposed to so I had a look into my mail server logfile. With the tailf -command I would be seeing the messages to and from the mail server. But as I was looking at little to no action the logfile suddenly was filling my screen with messages.

Someone was trying to use my mailserver....

Encrypted storage

In case you have documents and files you don't want anyone to be able to see there is always the possibility to use truecrypt. Truecrypt will let you use a file or partition as an encrypted storage. It is easy to use and not at all hard to understand. It also supports Linux, Windows and Mac so you can use it on whatever platform you wish.

Truecrypt is no longer safe.
Check their website before using it.

You can even encrypt part of an USB-pendrive and include the files for running the truecrypt program on the USB-drive. This way you will be able to use you USB-device on other computers without needing to install the package on the computer you are working on. (But you will need admin privileges.)

To download TrueCrypt head over to their web-site. Go to the download page and download the package for your platform. After downloading the Linux gzipped tarball you simply extract it and run the truecrypt installation-file.

Step 1:
Run truecrypt to open the GUI for the program and create a new encrypted volume. Using a file is as it can be. Click on Create Volume, select the folder to put the file in, and give it a filename. Follow the instructions to set the encryption, password and any other option.

Step 2:
In the TrueCrypt main window select the slot you want to put your encrypted volume in, click on Select File and navigate to the file you created in the previous step. Click on Mount and type your password for the encrypted filesystem when prompted.

Step 3:
Add files or folders to your encrypted filesystem as you do to any filesystem.

That's all there is to it.
Easy and well functioning way of keeping some documents private.
To use a portable USB-drive check the documentation on TrueCrypt web-site.

Linux Tutorials

Linux has become the preferred OS for me and my company. Not only for the fact that it is free, but also because of the possibilities it gives us.

For a small company as ours Linux is the perfect solution. It provides us with a stable and secure platform for our servers running mail, webserver, fileserver, printserver, automated backups and a lot more.

Of course we need to know a thing or two about installing it and setting up the various components . And I am always looking for more information on how to configure and setup different parts of Linux and other Open Source Software.

Recently I found out that linux.org had redesigned their site and of course I had to take a look at it.

Linux Project Blog

This blog is about using linux to do different things. We will be using both server and desktop versions. Since Linux have so many different flavours I find it easier to stick to one distro for both my server an desktop. Currently this is Ubuntu LTS editions. I prefer LTS editions because I find updating every 6 months to be too often and the differences are small between the versions.