Rrd4j caching

hello,

I want to switch on the caching from the rrdtool (rrdcached). I understand to configure the rrdcache, but I do not know, how to start the rdd4j persistence in the daemon mode.
Do anybody know how to get working the rrdcache with the rdd4j presistence.
The reason for that is to protect the SD Card in my raspberry.
Thanks
Harald