Hi @rmaryada! Welcome to the SonarSource Community!
In your case, your upgrade path is like so: 6.7.4 LTS -> 7.9 LTS -> 8.5.1
This means you will need to upgrade to 7.9 LTS then you will be able to upgrade to 8.5.1.
- Please first read our instructions on Upgrade the Server and the Release Upgrade Notes. The latter will be very important when you upgrade between versions, so please familiarize yourself and read these notes to avoid any surprise regressions, deprecation notices, and more.
- Read through the Upgrade Guide and follow the instructions. You will need to backup your database, any custom plugins (8.5.1 now includes the core plugins already, see here for more), and the
sonar.propertiesfile, just in case.
If you have any more questions, create a new thread and we can help you there.
Joe