Why such an old version?
Remember that you can only restore a backup to the exact same version it was made on, so if you need to restore a backup made on 8.9.6, you need to install a new server with 8.9.6.
If you don’t have a backup, you’re in a bad position. I didn’t take over administration of our GitLab installation until we were on 10., so things might have been different (but I suppose it wasn’t much easier) on 8.9.6. Data is spread in multiple places, the most important are probably:
- repositories in
/var/opt/gitlab/gitlab-data/repositories (That’s the path used for omnibus installations, for source installations I believe it’s different, but I don’t remember, neither what it is or where to find it)
- GitLab internal data in a database (on 8 mysql was supported in addition to PostgreSQL, that is the only supported option today)
but there’s also:
- other build data
- LFS data (if enabled)
- uploaded stuff
I would guess the route of least trouble is to try to get you GitLab running again, and then upgrade it, and implement a good backup strategy.
What did you do when GitLab stopped working?