The nagios database is generally stored where the Core (Poller) server is. The others, nagiosql and nagiosxi are generally offloaded together, otherwise they will remain with the XI server. Obviously if you offload any of the MySQL servers then the data will go there instead of the original server you offloaded from.tmcdonald wrote: Within the nagios database you have generally your host/service information, state history, log entries, acknowledgements, and other status information. It is used by Core and the NDOUtils project in an XI setup to store data in the database for reporting purposes.
Inside nagiosql you have the information which is stored in the Core Config Manager, and is essentially all of the configuration information for your hosts, services, contacts, etc. Gets updated whenever you make changes in the CCM such as adding or removing hosts/services.
nagiosxi holds information specific to XI, such as user accounts, dashboards, site preferences, and language settings.
The files (RRD, logs, etc.) should still remain on their original servers though.