The backgrounf process
diskjournald tracks volume mounts and un-mounts. If Volume Presence monitoring is enabled, it will also trigger a full run of diskjournald when a monitored volume goes offline.
The Watchman Monitoring agent performs its diagnostic checks once per hour, as schedule by launchd. In addition we include a background listener to track when volumes are mounted and unmounted.
This information stored by diskjournald is used by the plugins on the computer itself, and is included in reports only in relation to a configured Warning or Alert.
Diskjournald is required for the proper operation of a number of Watchman Monitoring plugins, as well as in the PreferencePane when configuring notifications. In the event that diskjournald is not running, the PreferencePane will display the message "ReasonCode 412". Please contact Watchman Monitoring support for assistance in diagnosing the cause, and allowing us to help with resolution.