I've been managing a small instance since version 5. There have been a few hiccups here and there, but mostly due on my part to not reading the release/upgrade notes carefully enough. Since version 8/9 it has been absolutely pain free. Run apt-get update then apt-get upgrade wait a bit and enjoy the new release!

It's basically maintenance-free, and if you got trouble, you can ask in Issue Tracker https://gitlab.com/gitlab-org/gitlab-ce/issues. We can advise how you can recover your instance case-by-case. (Also, there is a feature for backup your local data to cloud storage https://docs.gitlab.com/ee/raketasks/backup_restore.html. This is useful in case your machine'HDD died suddenly)

To troubleshoot your problem smoothly, I'd advise not to modify your GitLab instance intentionally, for instance, applying own custom patch, changing database schema, etc.

I admin it for a small team of around 25. I've never had a failed upgrade, and have managed better uptime than Github and Gitlab, as it never gets DOS'd.

I'm running GitLab via Docker, and I love it.

I previously managed Atlassian instances and I dreaded ever touching the servers.

GitLab def has there shit together in this regard.

edit: I forgot, when issue, their docker container uses tmp memory that never seems to free itself. I occasionally (once a year) have to rm and recreate the container, which isn't a huge deal for me.

I maintain several Atlassian products in addition to Gitlab on Ubuntu. Definitely agree - we have a whole snapshot / backup databases routine before going near the Atlassian boxes.

On-premise runs pretty much maintenance free. I've be running GitLab for ~5 years on-premise with ~200 developers. The issues have all been minimal, and few, over those years.

Why not cloud Gitlab?

There are use cases where on prem is either very attractive or a requirement. We are currently on Github, but there part of me that would really really like to avoid spreading our code all over the Internet (we also use hosted CI) and trusting others. (Yes, Github is probably better at security than me etc ....) However others have very high security requirements where regulations are being violated by being off prem.