Hebelwirkung am EFSF – “Wohl ist des Hebels Macht, wenn er denn richtig angebracht”

Politische Diskussionen sind üblicherweise keine Begründung für mich einen Blog-Eintrag zu verfassen. In der aktuellen Streitfrage über die Verwendung einer “Hebelwirkung” für den zukünftigen “Eurorettungsschirm” (EFSF) erscheint mir allerdings “Not an der Tastatur” zu sein, denn es wird viel über die möglichen Handlungen berichtet, allerdings die Konsequenzen aus dem Handeln nicht transparent gemacht. Continue reading ‘Hebelwirkung am EFSF – “Wohl ist des Hebels Macht, wenn er denn richtig angebracht”’ »

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Subversion Installation on Debian with Plesk – Without Security Issue

Available at http://www.bluehelp.de/tutorial/svn-debian-plesk.html there is a good (German) description on how to set up a Subversion repository on a Debian system if also Parallels Plesk Panel is installed. However, there is one thing that needs improvement there: When generating the HTTP password file with the two commands it happens with

htpasswd –cs /var/svnrepo/dav_svn.passwd alice
htpasswd –s /var/svnrepo/dav_svn.passwd tom

However, this implies that the password file is being generated with unix rights rw-r–r– and author/group with the current user. It is well-known that password files which are world-readable are bad idea in any case and cause a security risk.
Thus, I would like to enhance the statement on that page there by recommending to issue the following additional commands:

chown .www-data /var/svnrepo/dav_svn.passwd
chmod o-r /var/svnrepo/dav_svn.passwd

By this the file still is readable by the Apache Webserver, but no “other” users will be allowed to read the contents of the hashed password file.

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Acer’s WebCam Windows XP not shutting down anymore

Sometimes you could go nuts: Having sent in an Acer TravelMate 7730G to the German Acer Support for replacing the mainboard, it turns out afterwards that the operating system does not shut down properly anymore. After some long time googling around you detect that this might be related to the driver of the integrated WebCam. The device manager reports it to be a “Acer Crystal Eye Webcam” wheras the manufactor of the driver is Suyin.
Many forums on the web recommend to reinstall the driver to fix the problem, however, that turns out to be not successful in this case. Only after I detected this post I got the important hint: it’s the point that the power management of this driver does not work well. By deactivating the power management of the USB root hub to where the camera is attached, you are able to fix the problem. How to detect the root hub in question is a bit more complex than stated at the post there: As the camera itself is a composite USB device, the hardware that is connected to the hub is not the camera itself, but the composite device. At the end you need to look out for an USB root hub where the composite device is attached to. After finding that fixing the problem was a piece of cake (see recommendation provided by the post mentioned above).

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Funny Linux Kernel

In knew that Linux is a funny thing, but that its kernel is humorous was new to me today when I entered the following command into the command prompt:

lenny:/# cat /proc/swaps
Filename                                Type            Size    Used    Priority
/dev/null                               partition       1048576 3440    -1

Swapping out main memory pages into /dev/null might be performed very efficiently, however, I doubt that reading them back will be as easy.

The solution to this miracle is very short: The funny linux kernel is running in a virtual machine environment. The swap partition is out of its domain and thus it does not know how to reference to it.

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Strongswan on the Excito Bubba3 Server

Having become a proud owner of a Bubba3 server, I was very pleased to make notice of two facts: Excito, the manufaturer of the B3, has built the system internally on Debian Squeeze and provides (though unsupported) additional information via Wiki pages how to leverage any functionality that is available with this distribution, if supported by the system’s architecture (ARMEL). My special interest has been caught by the wiki page explaining how to install a VPN client/server on the box as in my system setup at home, I need this feature to allow access to the internet. Though the description is very accurate (kudos to you!) and easy to follow, I still had the impression that a normal user should not be forced to recompile the kernel delivered natively by Excito. Continue reading ‘Strongswan on the Excito Bubba3 Server’ »

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Wie journalisitischer Junkfood die Politik gefährdet

Stellen Sie sich doch die folgende Situation vor:

Der Papst unternimmt eine Reise, auf der er ein AIDS-krankes Kind besucht. Er segnet es und dem Kind geht es daraufhin eine kurze Zeit lang besser. Einige Tage darauf verstirbt es allerdings recht plötzlich. Tags darauf titelt eine Boulevard-Zeitung:

Papst tötet Kind – war es Mord?

Was ist geschehen: Der Papst hatte eine noch nicht ausgebrochene Virusinfektion. Durch den nahen Kontakt mit dem Kind hatte er es mit dem Krankheitserreger angesteckt, wogegen es nicht mehr genügend Abwehrkräfte besessen hatte.

Da Zeitungen mit ähnlichen Schlagzeilen auf “Seite 1” täglich millionenfach gelesen werden, stellt sich für mich in solchen Fällen – neben der vielleicht juristisch interessanten Problematik – die Frage nach der Größe der Chuzpe ihrer Autoren. Continue reading ‘Wie journalisitischer Junkfood die Politik gefährdet’ »

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Die Bringschuld der Bürgerschaft

In der heutigen Veranstaltung im Gewerkschaftshaus in Mannheim hat der designierte baden-württembergische Ministerpräsident Kretschmann für seinen Koalitionsvertrag bei den Bürgern geworben. Im überfüllten Otto-Brenner-Saal zeigte er oftmals auf eine selbstironische Art und Weise einen ganzen Strauß von notwendigen Änderungen im “Ländle” auf, akzentuierte aber insbesondere den notwendigen Anpassungsbedarf in der Sozial- und Bildungspolitik. Insbesondere in Bezug auf Infrastrukturprojekte (hierbei zeigte er auf, daß dies nicht nur auf das Hauptthema “Stuttgart 21” reduziert werden darf) machte er deutlich hier stets ein abwägen von übergeordneten Zielen mit den lokalen Besonderheiten stattfinden muß und daß dies die wesentliche Herausforderung der Politik ist. Dem lobbyistischem System erteilte er in diesem Bezug eine klare Absage.
Die für mich wichtigste Aussage des Abends fokussierte sich allerdings in einem sonst für die Politik ungewöhnlichen Aspekt. Herr Kretschmann sprach im Rahmen eines solchen Findungsprozesses von einer beiderseitigen Bringschuld: Auf der einen Seite hat eine Regierung eine Bringschuld Entscheidungen zu treffen und diesen entlang der verfassungsgemäßen Grundlage parlamentarisch voran zu treiben; auf der anderen Seite hat allerdings “auch die Bürgerschaft” (Zitat Kretschmann) die Bringschuld, Themen sachlich und konstruktiv zu behandeln und zu diskutieren, um eine Entscheidungsfindung herbeizuführen. Er nannte dies den “zivilisierten Streit”. Dies muß allerdings hart am Thema geschehen und darf nicht in Demagogentum ausarten, da sonst dem Populismus Tür und Tor geöffnet wird und der konstruktive Diskurs unterbunden wird. Er band damit insbesondere an die Forderungen des “mündigen Bürgertums” an, das in den letzten Jahren drohte zu versiegen.
Wenn aus meiner Sicht der neue Ministerpräsident es nur schaffen sollte, diesen letzten Punkt konsequent in der nun kommenden Legislaturperiode zu leben und somit im politischen System Deutschlands salonfähig zu machen, so hat er sich aus meiner Sicht mehr als einen “Stern in der Hall of Politics Fame” verdient – gleichgültig ob er es nun schafft, neue Kita-Plätze entstehen zu lassen oder nicht.

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Comparing an Enterprise Application with a Search Engine

In his just-released book “In-Memory Data Management” Prof. Hasso Plattner and Dr. Alexander Zeier are comparing enterprise applications with web search systems (cf. section 1.1, page 8 – download excerpt). However, I think one should be careful with that and know the major differences which are not obvious at first glance. As an example I would like to compare a financial reporting – representing the Enterprise Application class – with a classical search engine to better visualize two fundamental differences:
Continue reading ‘Comparing an Enterprise Application with a Search Engine’ »

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Windows 7 Home Premium and QEMU in SMP mode

I recently played around with a Linux Kernel as host operating system and having Windows 7 Home Premium as guest. My intention was to implement an easy-to-use sandbox system for someone in my family (a good starting point may be here). The hardware should be a Core 2 Duo processor. As he will most likely end up using only the sandbox and never really touch the host system, the maximum amount of resources (including memory and CPU power) should be handed over to the guest operating system. However, thinking that this should be quite easy turned out to be non-trivial in the end. Continue reading ‘Windows 7 Home Premium and QEMU in SMP mode’ »

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Logon with SSH takes long until the password prompt is being displayed

Since some time I experienced the problem that it took me ages to logon via SSH to some of my maintained servers on the web until the password prompt is being shown on the command line. After googling a bit I found a post describing my problem which I would like to recommend to the public. Root cause seems to be a missing configuration of the GSSAPI module. Instead of configuring it you may also simply disable this authentification method in /etc/ssh/sshd_config by specifying

# GSSAPI options
GSSAPIAuthentication no
#GSSAPIAuthentication yes
GSSAPICleanupCredentials no
#GSSAPICleanupCredentials yes

That solved my problem immediately.
However, against what’s written in the wordpress post, I had another error behaviour:

debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure.  Minor code may provide more information
Credentials cache file '/tmp/krb5cc_0' not found

debug1: Unspecified GSS failure.  Minor code may provide more information
Credentials cache file '/tmp/krb5cc_0' not found

debug1: Unspecified GSS failure.  Minor code may provide more information

And also please note that the IP address of the calling machine has a valid DNS reverse address. So, there still seems to be something else out there…

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