Migrate data to another gitlab server without deleting

Currently we have two servers containing gitlab. We would like to migrate the data from one server to the other but without deleting any repositories, projects, etc on the server we are migrating the data to.

Try using the inbuilt export tool available with GitLab,

Ref: Migrating projects using file exports | GitLab

No data will get deleted while following this method. But make sure to compare the data in origin and destination GitLab accounts once after the migration

Previously I have noticed “merge requester names” will get changed with the user that importing projects to the destination GitLab account.