For your Information: I had this Message twice since I upgraded to 9.5Beta. I never had this before, so I guess it's somehow related to beta. System is a SG 210 Rev.1 which was upgraded from 9.411.
RRD cache daemon not running - restarted
--
System Uptime : 7 days 21 hours 5 minutes
System Load : 0.26
System Version : Sophos UTM 9.470-14
Please refer to the manual for detailed instructions.