Using migratory network file system topologies, client file locks are managed by a file lock manager on a primary server. A network file system tracks all client file locks on the primary server. New file locks are identified and retained to support future migration of network file system service to an adoptive server. When a migration of network file system services is needed, the retained file locks are conveyed to the adoptive server. The adoptive server is forced to recognize the conveyed file locks.