Website updated

So, this was quite a job.. The previous version of the website was basically unmaintainable.

It was a huge job, but it is now converted to hugo, which makes it a lot easier.

My nephew (graphical designer and system admin, see Coming to your office) redesigned the site for me, so finally something that looks a lot better 😊

Thinkpad T440s keyboard backlight

A while back I made a simple python script to get the keyboard backlight of the laptop to dynamically switch on and off. Normally you control the backlight with a key combination. But I prefer to only have backlight when I’m typing.

The newer version of the script uses the /sys kernel interface to change the backlight. The older version was quite a hack, poking around some bytes. You can still find it on github.

The newer version can be found on github as well:

Wifi christmas tree coding

Since the last posting I connected the christmas tree to an esp8266. I used a Wemos D1 mini for this, which is a very nice and complete board to develop with.

For more info, see the Wemos website.

I used the basic Arduino environment with the Arduino esp8266 extensions to develop the code. There is lots of information on the internet on how to set that up, so I’m not going to put that in this posting.

What I wanted to get working is a setup with the following features:

Wifi christmastree

While browsing through the Kwantum folder, I found an intresting, small and cheap christmastree.

It consists of 10 leds, powered by 2 AA batteries. No thrills or whistles. So I decided to buy one and see if I could mod it a little.

Unpacking the tree, and all seems to look ok.

And after inserting batteries it even lights! 😊

My idea would be to remove the leds, put in RGB leds and let the leds be controlled by an ESP8266 microcontroller with a webinterface.

C1 exhaust

Final write up of my 2013 attempt at upgrading the exhaust of my C1.

Speedster rotrex

Decided to finish up writing on the Rotrex installation on the Speedster. Have had some requests about how the setup was done. Some links below.

• Rotrex supercharger installation
• Rotrex ECU calibration

Speedster update

Finally got around to updating some of the content on the Speedster projects.
I finished writing the following pieces:

• 3" Exhaust installation
• 3" Exhaust ECU calibration

Proxmox 4.1 lxcfs

Since Proxmox 4.1 I’ve had a number of issue’s on my servers.

The first (and smallest) issue has to do with my Thinlinc installations. The agent component can hang after running a specific cronjob. A “ps” process starts to hang. The only way to resolv this is to restart the zone. This behaviour seems to be related to the lxcfs package on version 0.13-pve3. Later versions seem to resolve this.

The second issue was much more of a problem. This manifests itself as a server with very high load (>12), lots of processes (normally 1400, now > 10.000) but otherwise responding fine. Everything that is running in the lxc containers seems to hang on IO. While checking the processlist further (before rebooting the server, as this seems the only way out), the output of pstree shows something intresting.

Happy newyear!

Happy new year! First thing I did is finished a short writeup on the Battery Brain in the Speedster 😊

Proxmox 4 migration issues

With the introduction of Proxmox 4 a rather large change was introduced. The combination of KVM and OpenVZ was changed to KVM and LXC. The big upside of this is a recent kernel, changing up from 2.6.36 (released 2010) to 4.2 (currently).

But with the change from OpenVZ to LXC come some changes which make a migration less trivial (depending of the amount of features that are in use with OpenVZ).

The Proxmox Wiki has some good information on migrating from Proxmox 3 to Proxmox 4. I have a couple of issue’s I ran into during a couple of migrations that I will share here. Maybe it is of use to someone else. Keep in mind I only run Debian containers, so other distributions might have other issue’s.

Thinlinc reverse proxy

I ran into this program a while ago when I wanted to run the HTML5 ThinLinc client behind a reverse proxy. The HTML5 client has a number of references in it (and a redirect) that refers to the root of the webserver. So serving the client from a url like

just doesn’t work.

But we have nginx and with some pointers from the excellent people at Cendio I got it working 😊

To make the setup a little bit more clear, I wanted to do this:

Veeam Jaguar fix

The other day there arrived a package for me at work from Veeam. Having ordered nothing and having to do nothing to do with VMWare I was confused.

Unpacking the parcel showed a Jaguar remote controlled car with the Veeam logo on its roof.

It was obviously a marketing ploy, because the car was missing the remote!

But they missed one thing… They sent it to a unix engineer! 😊

So like with any good car build, I started by stripping out the interior.

MendelMax 2.5 Z axis support

One of the problems I have with the MendelMax 2.5 is the Z axis. The binding of the axis was and issue and the threads that were delivered with the kit had a huge wobble.

I already started to modify the axis by using the “floating” setup, where the lead screws are detached from the X axis. I used this setup:

Ohmeye z axis isolation

This wasn’t enough and I ended up reengineering the whole Z axis setup. The last part was a support for the lead screws, so they were no longer hanging from the stepper motors. The idea is that we put bearings below the lead screws so they are supported, can rotate freely and have no side to side movement.

Cheap but good headphone

At work I need some headphones so I can close myself off and concentrate on a specific job. I don’t want some cheap sounding headset, because I know the sound quality will anoy me and I won’t use it.

After searching on the internet, I found a nice option, the Superfux HD 681.

This headset got pretty good ratings and sound was especially good after applying the “mod”.

What mod? I searched for a bit, and found this document:

rss2mantis script update

I’ve been running with the script for a while now, but I found that in some cases no new issue’s were created when they appeared in the RSS feed.

The script stores the local time in the feed status file. When retrieving the RSS feed it compares the RSS feed timestamp to the local time in the status file. Even with timezome compensation, this seems to be an issue.

I created an update of the script where the status file stores the timestamp of the newest RSS feed item the script has seen. This seems to work much more reliable.

Security alert monitoring

Finally had time to do a bit of a write up on the security alert monitoring I’m using with Mantis. I’m pretty happy with, works good for what I need 😊

Security alert monitoring

I was looking for a setup which would automatically monitor new security issue’s that arrise, notify me about them and provide a way to follow up on those issue’s. I couldn’t really find anything that would fit those requirements and be as simple as possible. So I decided to look at it from a different angle: get a bug tracking system which has an interface and feed the system from a script that monitors the security issue’s.

After browsing for a bit, Mantis BT came up as a good candidate. It looked like a simple enough setup, yet it provides a SOAP interface and seems to have more then enough features to track issue’s.