We have Ubuntu LTS 14 and GitLab version 11.8.1 hosted on AWS. I would like to know what are the steps to upgrade from this release all the way to the latest version and what issues to expect. Thanks alot.
Take a backup first (full VM snapshot recommended).
Issues to expect:
Upgrading from 11.x to 12.x to 13.x to 14.x to 15.x requires a lot of upgrade steps and database migrations. Plan with downtime, depending on how big the environment is.
Ubuntu 14 LTS is quite old, too. In between the GitLab major versions to upgrade, you may need to upgrade the Ubuntu distributions too, because newer GitLab packages will have dropped support for Ubuntu 14 LTS becoming end-of-life. Supported operating systems | GitLab
When you’re that far behind, there is a good chance not all of the GitLab versions you need to go through are released for any of the versions of Ubuntu you will have to go through.
My suggestion would be to upgrade as far as you can on one LTS version of Ubuntu, and then go to the next (i.e. lucid->trusty->xenial->bionic->focal->jammy if my memory serves me, the company - wisely - used Debian before someone - unwisely - made us change to Ubuntu around xenial). I have no idea how all those ubuntu upgrades will work, but they will probably cause more work than upgrading GitLab, but this way you should not encounter a situation where the version of GitLab you need was never build for the version of Ubuntu you have. In the extremes, I don’t believe Ubuntu 14.04 ever got GitLab 15 and Ubuntu 22.04 hasn’t got anything older than GitLab 15.5 (specifically it doesn’t have 11 that you’re on).