I need to migrate all archive messages from Openfire 3.10.3 (Monitoring Service plugin 1.4.2) to new Openfire 4.4.1 (Monitoring Service plugin 1.8.0). How I can to do this correct ? Simple mysqldump not affected this.
The most safest course of action is to restore the old server (Openfire 3.10.3 with Monitoring 1.4.2) that makes use of that database, then upgrade Openfire and the Monitoring plugin. The update scripts should apply all required changes.