I suggest you take a break and rethink your approach.
If you want to use openHABian, use openHABian-supported hardware (SSDs are not) and openHABian-provided tools such as the SD mirror setup menu function and the Amanda backup software.
Or refrain from using openHABian and do on your own server project.
Use whatever hardware, OS and tools you want, but do it on your own.
Please don’t ask on the openHAB forum how to do it, that’s not what the forum is there for.
Please do not ask people to help with mixing these approaches. It’s ultimately a waste of time on your and everybody’s part and will not result in a stable setup when you are not 100% aware of all the relevant details and I don’t think you are.
Sorry to you and anyone this may sound rude to - this is not my intention, my intention is to help you (the original poster) find a working solution quick and with as little efforts possible to anyone.
Thank you for understanding.
Recommended readings:
how to ask a good question
openHABian availability and backup features
support of running a modified openHABian setup
On SD cards and flash corruption