I have this error: error only systemd is supported
you need to read through the forum here, identifying your Synology architecture first… I used to ( a long time ago) run home assistant in docker on my NAS, but subsequently moved to a dedicated NUC. From what I have seen, I know it is possible, you just need to read up a little… I am sorry I can’t help you any further…
Just run faced the same error: “error only systemd is supported” with my old Ubuntu 14.04 during Hass.io installation.
14.04 did not supported systemd, upgraded to 16.04 and got it working.