I am trying to upgrade sonarbube from 8.9 LTS to 9.0 with postgresql

Hello Team.

I am planning to upgrade sonarqube 8.9 lte to 9.0.
facing below error message. after maintenance its not asking for upgrade database.

SonarQube is under maintenance

Hey there.

You really shouldn’t target any version other than 9.4 for upgrade, as all other v9.x versions are considered EOL.

While the SonarQube is under maintenance is expected if you only browse the root URL of your SonarQube instance, appending /setup/ (like https://next.sonarqube.com/sonarqube/setup) should allow you to trigger the migration.