Ich have the newest firmware on DS213, and I installed OH2 but without success. Can somebody help? for example with a tutorial or similar?
Hi,
Did you read this? Did you do all steps?
Also, check out this topic: Synology Diskstation.
In order for us to help you, we would need to know which Synology package you have installed and what error you have.
Hi !
okay, now it works partly. 
I connected homematic with openhab and openhab found all things. thats also good.
but now, I am configure the items and a basic sitemap, but openhab cannot found it.
I found these lines and change the conf directory to public. is that the problem?
here are the lines:
mkdir /volume1/public/OpenHAB2
mkdir /volume1/public/OpenHAB2/conf
cd /volume1/@appstore/OpenHAB2/conf
cp * /volume1/public/OpenHAB2/conf
cd …
rm -r conf
ln -s /volume1/public/OpenHAB2/conf /volume1/@appstore/OpenHAB2/conf