Wed Dec 28, 2011 4:44 pm
None of the Routerboards have persistent clocks so when you reboot they'll be reset to default. That's why it's important to set up NTP when working with them so your edge router can pull time from the Internet and then distribute it within your network.
As for graph data, it's memory resident so you loose it when you reboot. If you want something more persistent then you'll have to set up something external like MRTG.