# Praefect Rake Tasks > [Introduced]( https://gitlab.com/gitlab-org/gitlab/-/merge_requests/28369) in GitLab 12.10. ## Replica checksums Prints out checksums of the repository of a given project_id on the primary as well as secondary internal Gitaly nodes. NOTE: **Note:** This only is relevant and works for projects that have been created on a praefect storage. See the [Praefect Documentation](../gitaly/praefect.md) for configuring Praefect. **Omnibus Installation** ```shell sudo gitlab-rake "gitlab:praefect:replicas[project_id]" ``` **Source Installation** ```shell sudo -u git -H bundle exec rake "gitlab:praefect:replicas[project_id]" RAILS_ENV=production ```