Recovering from a Hard Shutdown

Anytime the Historian service is unexpectedly shut down, there is a potential risk of file corruption when an HDB file is open for writing. When this happens, the file is marked 'Questionable' and must be validated for possible errors. This is handled by the background validation process, or the user can manually validate the file through the FILE OPTIONS menu.

If any errors are found during validation, the file is taken offline, at which point the user can recover it using the same FILE OPTIONS menu. Once recovered, the file should be manually validated to ensure its integrity.

Data Logging Paused

As of v26.3, a SaF stream logging data to a DataSet is automatically paused in the event of a hard shutdown. This prevents data from being written to the previous file while the current one is offline.

Once the current file has been recovered and/or validated, the SaF stream must be unpaused through the Store & Forward screen to resume data logging.

Email Alerting

Additional email alerts are sent in this scenario if the system is configured to send emails.