Please use code fences:
It should be:
Strategies {
everyMinute : "0 * * * * ?"
everyHour : "0 0 * * * ?"
everyDay : "0 0 0 * * ?"
}
Items {
* : strategy = everyMinute, restoreOnStartup
}
Did you restart OH after edit the rrd4j.persist file?