Chrony luci statistics, how to clear?

Installing and Using OpenWrt
1

The Luci statistics applet for chrony seems to remember every source host IP that chrony used since it was installed. The list grows without bounds, because every time the pool DNS name resolves to a new IP it is added. So I end up with something like 40 sources in the graph ... most of which have only NaN data points.

Is there a way to change this behavior so only the current sources are shown? Failing that, is there a way to clear the data and start over? I tried this:

rm -rf /tmp/rrd/OpenWRT/chrony

which sure looks like it should help, but it doesn't.

2

All DBs are wiped during reboot, since they're stored it RAM.

If your DB survives a reboot, you changed the default storage folder.
Only you know where you put it.

Did you stop chrony before you tried to wipe the DB?

3

...or enabled the statistics backup option, which nicely stores statistics to flash during orderly reboot.

That should help, but I am not sure if all individual data points are in chrony dir or if there are dirs or data files like chrony-xxx
You might need to use wildcard chrony*

Additionally, stop both chrony and collectd (the data daemon in LuCI statistics) services before delete action.