Tag Archive: linux


Code is an important asset to every company. Thus it is only in the company’s interest to protect their code base as good as possible.
While this sounds like an introduction you would expect in an article about proper backups or access control I think it is equally fitting for this article about Version Control Systems (VCS).

Those who work on the code are only human, and as humans we sometimes make mistakes. This can be because we don’t quite know what we are doing, but it can equally be a case of “shit happens”. And if “shit happens” you want to be able to respond quickly and undo whatever has been been done. Preferably without having to run down to the basement to get the tape with last (possibly full) backup. Of course a VCS cannot cover all kinds of situations, but it can help in a lot of ways to improve development and help out in case something goes wrong.

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Virtual once more: VPN

Remote access to servers should be secure. I guess we all agree on that.
Still there sometimes is no way around potentially insecure services like Remote Desktop or VNC. Or maybe you have servers that are not publicly accessible, because they are hidden behind a second firewall.

In order to both secure potentially insecure services and allow access to otherwise inaccessible servers you can use a Virtual Private Network, or VPN.

First of all I want to say that I think there are too many different implementations of VPNs out there. Windows seems to favor PPTP as it’s way to connect to VPNs. Aside from that there is L2TP, IPSec, OpenVPN and, if you want to count it as VPN, tunneling through SSH. And possibly a few more nobody really cares about.
Thus, when being given the opportunity to use such an encrypted connection the first question has to be what kind of VPN it actually is, because there is no one-size-fits-all configuration.
With IPSec being part of IPv6, and not just glued on top as in IPv4, there is hope, albeit little, that maybe, and just maybe, IPSec may establish itself as “the one VPN solution”.

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Working as a Network Administrator I, sadly, also have to deal with Windows servers. While this is bad enough in itself this article is not written as a way to rant about my general dislike of Windows, or even the lack of security often attributed to the Windows operating system.

This article, as the title states, tries to explain why I think that using Windows as a web server is an outrageously stupid idea.

Websites nowadays are not only tools where individuals and organizations present themselves, they are not pure advertising anymore, but often enough part of the product. But even when they are purely informational, no matter of what kind this information may be, they play a valuable part in corporate strategy. For this reason a website has to be available 25 hours a day, 8 days a week.

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(Mis-)Understanding IPTables

As now I am also maintaining a couple of firewalls I figured it might be a good idea to get familiar with their rulesets.
Frankly said, I was shocked.
Shocked by the number of conditions/rules that are used repeatedly in sub-chains for no particular reason, rules that have no effect, or rules that are plain pointless.

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screen is a very useful tool. It enables you to run tasks in the background without actually sending them to the background.
What this means it that you do not have the annoying side-effects of sending a process to the background using myterriblylongrunningprogram &, but you get a complete session that you can disconnect from and it will keep happily working away.

Now the problem with screen is that it opens the possibility to circumvent authentication.
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What to do with your new OS

Today I have found this tutorial on where to take Linux after installing it, as many new users who try it out seem to be lost at this point.
I think it’s a well written tutorial, a good suggestion for newcomers to Linux, but personally I feel it misses something.

After installing your system, doing updates, and so on the same question arises again: “What do I do next?”

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The Executioner: binfmt_misc

The Linux kernel offers a vast array of functions that can be influenced from userspace, accessible through virtual filesystems like /proc or /sys.
While some functions are well known and used by many, IP Forwarding for example, there are also many functions which are not so frequently used, and probably unknown to the majority of users.
Nonetheless there are some interesting ways to influence your system’s behavior.

One of these functions is binfmt_misc, a kernel module with the ability to make virtually any file executable.

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A while ago these two articles popped up in my Google Reader, and I figured I should keep them so I wouldn’t forget to blog about this.
The Perfect Server – Fedora 14 x86_64 [ISPConfig 2]
The Perfect Server – Fedora 14 x86_64 [ISPConfig 3]

I like Fedora. It’s the system that runs my desktop and my notebook, but, quite honestly, I wouldn’t consider using it for a server and there is a very simple reason for that: support time.

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You may have heard about ReactOS, the free operating system striving to offer full compatibility to MS Windows.
Will it ever grow up? After all, it has been under development for many years now and is still not more than an alpha version.

I have been giving ReactOS a try several times over the last couple of years, and while I think that it’s an interesting project with great goals, I still have some doubts about it.

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Some of you may know that I am an advocate of Free Software. Linux has been my primary OS for over 10 years now, which means that I still remember kernel 2.2, KDE 1 and a time where getting your sound working required recompiling the kernel. And I can honestly say that Free Software offers everything I need for my job and my hobbies, which includes tasks like programming, testing systems in virtual machines, some graphics and sound editing and also a couple of games.

I have started using Linux with Suse Linux 6.2, and have pretty much right from the start compiled all additional software from source. As time went by my base system became a bit dated, which caused me to reduce the installation to the bare minimum to get a running system, and compiled the rest.
I’m possibly the only person who has used KDE 3 and a 2.6 kernel on Suse 6.2.

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