How to start jenkins?

Solution 1:

Check the jenkins upstart configuration file /etc/init/jenkins.conf.

Verify that the path for JAVA_HOME is correct. On a fresh install, it may look like /usr/lib/jvm/java-default (or default-java), however, if you've used apt-get to install the java 6 jre, the directory is actually /usr/lib/jvm/java-6-sun

Solution 2:

If you change JAVA_HOME to /usr in /etc/init/jenkins.conf then you can use whichever Java implementation you like.

You can see your altenative installations of java with (as root - add sudo if need be):

update-alternatives --list java

You can set your java alternative with:

update-alternatives --config java