Upgrading across multiple versions is handled automatically. However, if in your migration path you have an LTS version, you must first migrate to this LTS and then migrate to your target version.
Example 1 : 5.1 -> 6.7, migration path is 5.1 -> 5.6.7 LTS -> 6.7.x LTS
Example 2 : 6.2 -> 6.7, migration path is 6.2 -> 6.7.x LTS (where x is the latest patch available for 6.7 - you don't need to install all the intermediary patches, just take the latest)
This is a generic upgrade guide, please read carefully the Upgrade Notes of your target version and of each intermediate version, if any (below).
If you are targetting to move to 6.7 LTS and to install a commercial Edition, please read this documentation.
Before you start, backup your SonarQube Database. Upgrade problems are rare, but you'll want the backup if anything does happen.
Download and unzip the new SonarQube distribution in a fresh directory, let's say $NEW_SONARQUBE_HOME
Install the plugins compatible with your version of SonarQube. Use the Compatibility Matrix to ensure that the versions you install are compatible with your server version. Note that simply copying plugins from the old server to the new is not recommended; incompatible plugins could cause startup errors.
Update the contents of sonar.properties and wrapper.conf files (in NEW_SONARQUBE_HOME/conf) with the settings of the related files in the $OLD_SONARQUBE_HOME/conf directory (web server URL, database, ldap settings, etc.). Do not copy-paste the old files.
If you are using the Oracle DB, copy its JDBC driver into $NEW_SONARQUBE_HOME/extensions/jdbc-driver/oracle
Starting with 6.6, there's an additional step you may want to perform if you're using Oracle. On Oracle the database columns to be dropped are now marked as UNUSED and are not physically dropped anymore. To reclaim disk space, Oracle administrators must drop these unused columns manually. The SQL request is
ALTER TABLE foo DROP UNUSED COLUMNS. The relevant tables are listed in the system table
Refreshing your database's statistics and rebuilding your database's indices are recommended once the technical upgrade is done (just before the very last step).
For PostgreSQL, that means executing
VACUUM FULL. According to the PostgreSQL documentation
In normal PostgreSQL operation, tuples that are deleted or obsoleted by an update are not physically removed from their table; they remain present until a VACUUM is done.
Check the documentation pages of the Scanners you use to see if upgrades are available.
If you use external configuration, such as a script or Windows Service to control your server, you'll need to update it to point to NEW_SONARQUBE_HOME.
In case you used the InstallNTService.bat to install SonarQube as a Windows Service, run the OLD_SONARQUBE_HOME/bin/.../UninstallNTService.bat before running the InstallNTService.bat of the NEW_SONARQUBE_HOME.
Usually SonarQube releases come with some specific recommendations for upgrading from the previous version. You should read the upgrade notes for each version between your current version and the target version.