Edge Panel Alarm History/Trend Retention

I realize that there is the limitations on the Igniton Edge Panels.

I have a question around the Trends/Alarm History retention when it is being used purely as a standalone HMI not connected to any Ignition Gateway.

To my understanding the limit is 7 days of buffering for Trends and Alarm History?
Also if the Edge gateway is shutdown/loses power, when it starts up is the information for the last 7 days still there or is it volatile?

7 days of alarm journal history, and either 10 million records or 7 days of tag history data (whichever is reached first) is stored on-disk in (separate) SQLite database files.