Arm on NAS

For my hobby I´ll trial ARM to rip CD. For my Linux-NAS I can only use docker-arm. My docker-script shows this Error: 

Error response from daemon: create home/arm: "home/arm" includes invalid characters for a local volume name, only "[a-zA-Z0-9][a-zA-Z0-9_.-]" are allowed. If you intended to pass a host directory, use absolute path

I think I got this for:

-v "/volume1/home/arm":"/home/arm":rw \


What is the problem?



The 2nd question for me is´, how can I ensure, that the rip- Files will writte on my 2nd Harddisk?
I tried this:

-v "/volume2/HD/Medien/Music":"/Medien/Music":rw \