backup_restore from another server (v. 3.0.3)

Created by: ovanes

Just installed a new server with 3.0.3 and wanted to import the data from the other server which runs Gitlab 2.9. Transferred a backup from there and issued:

$ bundle exec rake gitlab:app:backup_restore RAILS_ENV=production

The above command resulted in an error:

Unpacking backup... [DONE]
gitlab_version mismatch:
  Your current HEAD differs from the HEAD in the backup!
  Please switch to the following revision and try again:
  revision: fa1f8513d999ea1efbd4ed8d1f24b272a475f0e5

How do I import best the data from one server to another?