[SOLVED] Need advice on alerts in collectd?

Question

Debian

Good evening!
I am preparing a Debian stable server for work.
Installed collectd, set up esmtp for the test and made an alert when the cache memory is loaded over 500MB
/etc/collectd/thresholds.conf

. And it works - the trigger works, letters come.

But I can't set up triggering for the sensors plugin
. There are no errors or indirect messages in daemon.log.
I tried this

and that

. The graph looks like this:

As I understand it, I incorrectly specify the data source.
I read the original manual, but I did not find anywhere how you can see the list of active DataSources suitable for firing triggers.
Thanks in advance for any help
UPD. Enabling modules for logging in debug mode had no effect. There are no messages about incorrect settings in thresholds.conf.
UPD2. I found the answer myself, working examples on Debian wiki

Answer 1

rrdtools info / dump will help you.