Linking the initial post on this topic: Gitlab NFS deprecated support
It would be best to keep the same discussion in the original thread. Opening a new one isn’t going to get it solved any faster.
You cannot continue with NFS, it’s deprecated, so you have to migrate away from it. I don’t use NFS so you’ll have to wait until someone who has already done this appears here and can offer you some advice or attempt to figure out a way yourself on how to migrate it.
You could attempt to use the gitlab backup and restore functionality to backup all your repository data stored on NFS, and restore this to a new installation of Gitlab that is configured by default with Gitaly. The backup can only be restored to the same version of Gitlab. So if the backup was from 15.7.0 it can only be restored to 15.7.0. Then you can continue upgrading after this. You can use your original gitlab.rb and gitlab-secrets.json from your original server but you will need to remove any NFS entries from gitlab.rb before attempting to run the new installation so as to make sure it’s using Gitaly. The default location for repository data, etc is /var/opt/gitlab or specifically /var/opt/gitlab/git-data/repositories. So you’ll need to make sure the new server has enough space to restore to. That’s probably about the best and easiest way to migrate that I can think of.
See backup and restore docs: Back up and restore GitLab | GitLab
If you cannot find a way how to do it, perhaps you need to think about purchasing support from Gitlab if nobody from the community has had a similar situation to you.