Debian Upgrade form Stretch to Buster

Today I updated my Debian system on my working mashine form Stretch to Buster. This is just a short reminder for myself. I followed the blog form nixcraft here.

1. Check version

First check your current version and note if you need it for fixing problems later.

$ lsb_release -a
 No LSB modules are available.
 Distributor ID: Debian
 Description:    Debian GNU/Linux 9.12 (stretch)
 Release:        9.12
 Codename:       stretch
$ uname -mrs
 Linux 4.9.0-12-amd64 x86_64

2. Update installed packages

First bring your strech up to date by updating all your installed packages

$ sudo apt update
$ sudo apt upgrade
$ sudo apt full-upgrade
$ sudo apt --purge autoremove

3. Update /etc/apt/sources.list file

Now you can update your debian package source list from stretch to buster. First check your current versions:

$ cat /etc/apt/sources.list

Now you need to replace the strech references with buster. This can be done quickly with the sed command:

$ sudo cp -v /etc/apt/sources.list /root/
$ sudo cp -rv /etc/apt/sources.list.d/ /root/
$ sudo sed -i 's/stretch/buster/g' /etc/apt/sources.list
$ sudo sed -i 's/stretch/buster/g' /etc/apt/sources.list.d/*

You can verify our new list

$ cat /etc/apt/sources.list 

Finally update you new package list

$ sudo apt update

4. Minimal system upgrade

In the next step you perform a minimal system update to avoid removing to much packages.

$ sudo apt upgrade

Answer question about restart of services wit ‘yes’

5. Upgrading Debain 9 to Debian 10

No you can run the real upgrade to Debain 10.

$ sudo apt full-upgrade

…this will take some time…

6. Reboot and Verification

Finally reboot your system…

$ sudo reboot

…and check the new version

$ uname -r
$ lsb_release -a

7. Clean up

Rund the autoremove command to get rid of old packages:

$ sudo apt --purge autoremove

Thats it! Have fun with fine tuning your new Debian Buster!

An Alternative for the Google App Postman….

Until today I worked with the Rest-API Testing Tool Postman from Google. But this tool was making me more and more suspicious in the last time. For example, you are recently asked to sign in with a Google account. So it was time to lookout for an alternative. And finally I found Insomnia. It is open source and hosted on Github.

To install the tool on Linux/Debian run:

# Add to sources
echo "deb /" \
| sudo tee -a /etc/apt/sources.list.d/insomnia.list

# Add public key used to verify code signature
wget --quiet -O - \
| sudo apt-key add -

# Refresh repository sources and install Insomnia
sudo apt-get update
sudo apt-get install insomnia

Maven on Debian failed with JDK 1.9 – ClassFormatError

Today I ran into a problem with Maven under Debian GNU/Linux 9 (stretch). My Debian has OpenJDK 8 as also OpenJDK 9 installed. OpenJDK 9 is my default java version. My Maven version is 3.3.9.

mvn -version
Apache Maven 3.3.9
Maven home: /usr/share/maven
Java version: 9-Debian, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-9-openjdk-amd64
Default locale: de_DE, platform encoding: UTF-8
OS name: "linux", version: "4.9.0-6-amd64", arch: "amd64", family: "unix"

The problem is, that building one of my projects results in the following ClassFormat Error:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.17:test (default-test) on project imixs-workflow-core: Execution default-test of goal org.apache.maven.plugins:maven-surefire-plugin:2.17:test failed: There was an error in the forked process
[ERROR] java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/xml/bind/JAXBException
[ERROR] at java.base/java.lang.ClassLoader.defineClass1(Native Method)
[ERROR] at java.base/java.lang.ClassLoader.defineClass(
[ERROR] at java.base/
[ERROR] at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(
[ERROR] at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(
[ERROR] at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(
[ERROR] at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(
[ERROR] at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(
[ERROR] at java.base/java.lang.ClassLoader.loadClass(
[ERROR] at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
[ERROR] at java.base/java.lang.Class.privateGetDeclaredMethods(
[ERROR] at java.base/java.lang.Class.getMethodsRecursive(
[ERROR] at java.base/java.lang.Class.getMethod0(
[ERROR] at java.base/java.lang.Class.getMethod(
[ERROR] at org.apache.maven.surefire.util.ReflectionUtils.tryGetMethod(
[ERROR] at org.apache.maven.surefire.common.junit3.JUnit3TestChecker.isSuiteOnly(
[ERROR] at org.apache.maven.surefire.common.junit3.JUnit3TestChecker.isValidJUnit3Test(
[ERROR] at org.apache.maven.surefire.common.junit3.JUnit3TestChecker.accept(
[ERROR] at org.apache.maven.surefire.common.junit4.JUnit4TestChecker.accept(
[ERROR] at org.apache.maven.surefire.util.DefaultScanResult.applyFilter(
[ERROR] at org.apache.maven.surefire.junit4.JUnit4Provider.scanClassPath(
[ERROR] at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(
[ERROR] at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(
[ERROR] at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(
[ERROR] at org.apache.maven.surefire.booter.ForkedBooter.main(
[ERROR] -> [Help 1]

The problem is a incompatibility of maven 3.3.9 with JDK 1.9. To solve this problem I switch to my OpenJDK 8 by setting the JAVA_HOME variable explicitly to JDK8 :

export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/

After this change maven install works fine again in my projects.

To make the JAVA_HOME setting permanent follow this stepts.

1. find your preferred java version

ls -la /usr/lib/jvm/

2. edit the file /etc/profile and add the following line with the path to the JDK 8 you find before:

export JAVA_HOME="path to jdk8 that you found"

3. verify you maven installation

mvn -version

You maven should now be set to JDK8.

I hope this post will become obsolete in near future.

Debian – user Bluetooth Speackerbox with Micro

Today I tried to connect a “August MS425” speaker box with my Linux Notebook running on Debian Jessie. To get the bluetooth connection running I installed the following additional packages:

sudo apt-get install pulseaudio-module-bluetooth, ofono, pavucontrol

After I established the bluetooth connection the speaker box was not working or displayed in the list of audio devices. To solve this issue I found this discussion.

The missing part was the the auto-connect a2dp option for the new device. So I had to edit the file “/etc/pulse/” and added the following line :

load-module module-switch-on-connect

After a reboot it works fine. You can use pavucontrol to setup audio settings.

VirtualBox no longer running in Debian

Today I had a strange problem with virtualbox in Debian Jessie which was no longer running.  When I start a virtual machine I got the following error message

The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or
there is a permission problem with /dev/vboxdrv. Please reinstall the
kernel module by executing

'/etc/init.d/vboxdrv setup'

But the problem was that the vboxdrv was not installed so I was unable to run that command. Alos reinstalling Virtualbox or the linux-headers did not solve the problem.

After all I found this discussion on stackoverflow.  I was able to solve the problem by installing a new version of Virtualbox from the backports by using the following command:

apt-get -t jessie-backports install virtualbox


Debian – Laptop Power Calibration

Since 2 years I have a Wortmann Ultrabook running on Debian. Since some weeks the the battery life has deteriorated sharply. I found this helpful article about the linux tool ‘powertop’.  You can use this tool to recalibrate the battery of a loptop using the following command:

sudo powertop --calibrate

At a first look it seems like this helped much to improve the power management of my laptop.

Linux Debian and Skype – no microphone

Today I had a strange problem with my skype installation in Debian. The microphone seems not to work. Finally I found the solution here.

The trick is the following:

  1. Open the Sound settings when you start a skype test call.
  2. Click on the tab ‘Recourding’
  3. Choose the option : show ‘all streams’ at the bottom of the tab
  4. Now when the skype call runs you will see the skype application appearing
  5. There is a tiny button muting the microphone. This option was selected in my case. Deselecting the mute button solved the problem for me

Eclipse Luna crashes on Ubuntu

Today I had strange problems with Eclipse Luna after an Ubuntu Update.
The solution was changing the eclipse.ini by adding


and changing the memory settings.
Thanks to Bård Aase Blog: