change the data directory gitlab to store repos elsewhere

Just updating in case people still refer to this. From the GitLab documentation:

By default, omnibus-gitlab stores the Git repository data under
/var/opt/gitlab/git-data. The repositories are stored in a subfolder
repositories. You can change the location of the git-data parent
directory by adding the following line to /etc/gitlab/gitlab.rb.

git_data_dirs({"default" => "/mnt/nas/git-data"})

Starting from GitLab 8.10 you can also add more than one git data
directory by adding the following lines to /etc/gitlab/gitlab.rb
instead.

git_data_dirs({
  "default" => "/var/opt/gitlab/git-data",
  "alternative" => "/mnt/nas/git-data"
})

Note that the target directories and any of its subpaths must not be a
symlink.

Run sudo gitlab-ctl reconfigure for the changes to take effect.

If you already have existing Git repositories in
/var/opt/gitlab/git-data you can move them to the new location as
follows:

# Prevent users from writing to the repositories while you move them.
sudo gitlab-ctl stop

# Note there is _no_ slash behind 'repositories', but there _is_ a
# slash behind 'git-data'.
sudo rsync -av /var/opt/gitlab/git-data/repositories /mnt/nas/git-data/

# Fix permissions if necessary
sudo gitlab-ctl reconfigure

# Double-check directory layout in /mnt/nas/git-data. Expected output:
# gitlab-satellites  repositories
sudo ls /mnt/nas/git-data/

# Done! Start GitLab and verify that you can browse through the repositories in
# the web interface.
sudo gitlab-ctl start