What is the default username and password for SonarQube?

username: admin

password: admin

http://docs.sonarqube.org/display/SONAR/Authentication#Authentication-AdminCredentialsDefaultAdminCredentials

If you are like me and have installed Sonarqube 6.4 using jdk 9 / jre 9 the login will always fail. This is due to the fact that java 9 is not supported. Please change the java version to 8 that is supported.

You can also point to a different java version in the conf/wrapper.conf file:

wrapper.java.command=/some/path/to/proper/jdk8

Valid jdk/jre options are found here: https://docs.sonarqube.org/display/SONAR/Requirements