Pebble Steel Black Matte

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Endlich lieferbar!

Endlich lieferbar!

I was very happy when I heard a couple of weeks ago that the coveted Pebble smartwatch can now also be ordered in Germany after a long time. Until now this was a problem due to duty difficulties. It seems like this difficulties have now been solved – ordering the watch in the Netherlands is now possible. After I’ve been waiting for a long time for this update I really had to order it instantly. The delivery time was quite short in spite of the huge demand. :)

Why Pebble?

But why did I choose the Pebble and not yet another smartwatch like the Samsung Galaxy Gear? Quite simple – I prefer the design concept of the smartwatch financed by Kickstarter for several reasons.

Pebble Steel

Pebble Steel

Other smartwatches try to combine smartphone technology with a compact clock case. As a result you’re wearing more or less powerful ARM devices with the Android operating system and color displays on your wrist. Disadvantages of this are short battery lifes and – in my opinion – overloaded operating systems.

The Pebbler watch is here more minimalist and only offers what I expect from a intelligent watch: displaying the time and establishing a connect to my smartphone. Color displays, a camera, a big memory and WLAN are missing. This might sound counterproductive but results in better battery life (up to 7 days). The pebble provides:

  • STM32F205RE Cortex M3 CPU with 120 Mhz
  • 128 KB memory
  • 4 MB memory for apps and watchfaces (clock face)
  • 4 buttons
  • Bluetooth 4.0
  • 144×168 Sharp e-paper LCD
  • 3 axis accelerometer
  • PeebleOS operating system, a minimalistic FreeRTOS derivate
  • Selectively a plastic (Pebble) or metal case (Pebble Steel) which is waterproof in up to 50 meters
  • Plastic, leather or aluminium bracelet (alternatively you can mount the most 22mm wristbands)

The smartwatch is connected to your iOS or Android device using the official Pebble app. After installation you can use the following functions:

  • Show notifications (E-Mail, Twitter, WhatsApp, Facebook, etc.)
  • Download apps and watchfaces
  • Control music

Developers will like the Pebble Software Development Kits (SDK) because it enables you to develop your own JavaScript and C applications for the smartwatch.

Pebble Apps

Using the Pebble App Store it is possible to sell and download applications. You can find a lot of useful apps – I’m using the following ones:

  • K9ToPebble – Mails received by Kaiten / K9 can be displayed as notifications (incl. text details), the Inbox can also be browsed using the menu
  • Multi Timer – stopwatch, countdown and lap counter, very useful to keep remaining time in mind during presentations


Red Hat Watchface (Watchface-Generator)

Red Hat Watchface (Watchface-Generator)

It is also very nice to have alternative clock faces. The offer is also very big here – I’m using the following watchfaces:

The Pebble Watchface-Generator is a very useful web application that can easily create clock faces for you – without having programming knowledge. After creating a clock face it can be downloaded by scanning a QR code. The watchface is installed on your watch using the official Pebble app.


After roughly 2 months I’m still very satisfied with the Pebble Steel – I can highly recommend having a look at the Pebble if you’re looking for a “unbloaty” smartwatch with a decent and timeless design without. I’m using this watch nearly every day and don’t want to miss it anymore. :)

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Short tip: Mount optical media under Solaris

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I’m not administrating Solaris systems very often – it is even more rare that I need to mount optical media on Solaris. This is just a short reminder so that I don’t need to use a search engine everytime.

First of all the CD / DVD drive is determined by the iostat command. Afterwards the drive is mounted using the first device slice.

# iostat -En
c8t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: VMware   Product: Virtual disk     Revision: 1.0  Serial No:
Size: 21,47GB <21474836480 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 4 Predictive Failure Analysis: 0
c7t0d0           Soft Errors: 0 Hard Errors: 5 Transport Errors: 0
Vendor: NECVMWar Product: VMware IDE CDR10 Revision: 1.00 Serial No:
Size: 0,35GB <349175808 bytes>
Media Error: 0 Device Not Ready: 5 No Device: 0 Recoverable: 0
Illegal Request: 1 Predictive Failure Analysis: 0
# mount /dev/c7t0d0s0 /mnt

Depending on the media type is might be necessary to select the file system (e.g. -o hfs).

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CentOS Dojo Cologne 2014

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This week the first official CentOS Dojo in Cologne was taking place. CentOS Dojos are one-day events where administrators and developers can exchange knowledge. Talks about recent topics are always part of these events.

inovex GmbH kindly features the event by providing their rooms and hearty catering. Beside coffee and cake there were many opportunities for smalltalk and making contacts. :)

The talks

Many interesting topics have been discussed in 7 talks:

  • Deploying foreman in enterprise environments with CentOS” by Nils Domrose
  • Keepalived & HA-Proxy as an alternative to commercial loadbalancers” by Jan Gehring
  • Running your own CentOS cloud with OpenNebula” by Jaime Melis
  • System management with Spacewalk” by me
  • Getting started with on CentOS” by Jürgen Brunk
  • Container Orchestration” by Timo Derstappen
  • Centralized and structured log file analysis with Open Source and Free Software tools” by Jens Kühnel

Many things were quite new to me – especially OpenNebula and Docker. I found no time so far to have a look at those products. The OpenNebula workshop by Jaime Melis was very comprehensive and interesting. Two hypervisor and particular virtual machines were configured and provisioned – so it was necessary to deal with the basic OpenNebula services to get along within the workshop. I heard a lot of Foreman but didn’t knew all the details about the particular functions. I’m really exited to evaluate the particular features in combination with Katello (the Spacewalk successor which comes with integreated Foreman). After some Docker container basics Timo presented tipps for orchestrating complex Docker setups. At least a very interesting but often forgotten topic was discussed: central standardized storage of log files.


inovex published recordings of the particular talks in the meantime – have a look at it: [click me!]


After reading a lot about CentOS dojos on social network I was very happy to having joined the first event in Germany. I really hope that additional events will follow in the future – the best would be to have similar nice locations. :)

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Short tip: File transfer from Android to OS X using MTP

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Files can be easily transfered from an Android device to Windows computer using MTP (Media Transfer Protocol). Unfortunately this protocol is not supported in Finder which means that you need to connect your smartphone as hard drive – if this function is supported.

My Android 4.4.x ROM isn’t supporting this function anymore – fortunately there is an application called Android File Transfer that expands MTP to OS X.

The application can be downloaded for free on the Android website. Connected Android devices are automatically connected if the screen is unlocked – and copying files is working like a charm. :)

Android File Transfer

Android File Transfer

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Short tip: Get Raspberry Pi temperature

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There is no standard sensor that can be used with lm_sensors to get the temperature of the Raspberry Pi embedded board – what a pity! Fortunately for this function there is a dedicated command called vcgencmd which is already included in the Raspbian image. To make it work you will need to customize the LD library paths:

# echo "/opt/vc/lib" > /etc/
# ldconfig
# /opt/vc/bin/vcgencmd measure_temp

There is also an appropriate file underneath /sys/class to get the temperature:

# cat /sys/class/thermal/thermal_zone0/temp
# awk '{printf "%3.1f°C\n", $1/1000}' /sys/class/thermal/thermal_zone0/temp
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OpenVPN under Mac OS X Mavericks 10.9

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OpenVPN connections can be established under Mac OS X using the free software Tunnelblick – I kept in mind.

Using the most recent OS X version Mavericks this is a problem. The stable version of Tunnelblick is not ready yet for Mavericks which means that it is necessary to use beta version. Unfortunately those were not working for me. It was possible to establish tunnels but afterwards any network connection was impossible. When having a look at the log I spotted the following line for a hundred times:

UDPv4: No buffer space available (Code=55)

Internet searches suggest that this is a OpenVPN client issue – I’m able to successfully establish connections under different platforms (Android, Windows, Linux, BSD). In some boards it was recommended to use older version of the Tunnelblick software – unfortunately this was also not working for me.

After wasting a couple of hours for troubleshooting I had a look at another software that is working fine for me: Viscosity

This tool looks like Tunnelblick but offers more individual settings – e.g. it is possible to customize the particular OpenVPN settings using a graphical user-interface instead of a text editor. If you are coming from Tunnelblick you can import your pre-existing configurations. There is a 30 days trial – the full version costs 9 USD.

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Akismet firewall problems (and how to fix them)

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Recently I was confused when I spotted several spam comments on my blog. After logging into the WordPress administration page I saw the reason for this issue:

Akismet has detected a problem. A server or network problem is preventing Akismet from working correctly.

Oops – where did that come from?

It seems like my hoster All-Inkl has updated its PHP configuration recently. The Akismet plugin needs access to particular external servers to filter Spam comments. I discovered  that the following PHP settings need to be set that this access works:

magic_quotes_gpc = 1
magic_quotes_runtime = 0
allow_url_fopen = On

If you’re using a managed webserver and don’t have the possibility to configure it entirely (like me) you can also set these parameters in the .htaccess file:

php_flag magic_quotes_gpc on
php_flag magic_quotes_runtime 0
php_flag allow_url_fopen On

After reloading the administration page everything was working like a charm again. :)

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Short tip: YUM error: “xz compression not available”

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While importing the recent EPEL7 YUM repositories I stumbled upon the following error:

# /usr/bin/spacewalk-repo-sync --channel epel-el7-x86_64 \
> --url \
> --type yum -c epel-el7-x86_64
Repo URL:
ERROR: xz compression not available

The solution was pretty easy – the following Python library was missing:

# yum install pyliblzma

The next import was working like a charm. :)

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