By default the Search data loggers write data to, and the warehouse loaders read event logs from, the logs directory of the server on which each component is running. This default location works if the loggers and loaders are running in the same server, but if they are on different servers, the loader components cannot find the log files.
For example, if you are using Search with Knowledge and Self-Service, you could have three servers named agent (running Knowledge), customer-facing, (running Self-Service), and management (running Search Administration and the SearchAdmin.datawarehouse module). By default, log files for Knowledge and Self-Service search activities are written to the agent/logs and customer-facing/logs folders. The data warehouse loaders in Search looks for the log files in management/logs. In this case, you could configure mDefaultRoot on the agent and customer-facing servers to point to management/logs, or configure that property on all three servers to point to some other location.
