Now we are talking 
best option (by far): mapdb
MySQL is way slower than MapDB for this purpose
one of the best options: InfluxDB+Grafana persistence and graphing
You can go with a 3rd one here: MySQL or use Influx. MySQL is more flexible here (export/replicas)
You can also achieve all 3 goals with MySQL as your persistence service. Grafana can also use MySQL as the backend DB and you can also do restoreOnStartup from MySQL.
If you want to use only 1 persistence service, go with MySQL using the JDBC driver.
For your setup, I would recommend a triple persistence configuration: Map + Influx + MySQL
Make sure that your host has enough RAM (~2G) to support all 3