The hardware is there (RPi + USB storage). The server software is there (NextCloud, Plex, n8n, etc). What isn't there is the plumbing. The next logical step after this blog post is making your services accessible to your phone over the public net. You'll immediately find yourself mired in domain name registration, VPS management, TLS cert management, dyndns, port forwarding, hole punching, etc etc. There are lots of…
I tried running nextcloud on an rpi. It just doesn't cut it. I had the 4gb model and nextcloud runs but its a horrible experience. You go on the web UI and click a photo and it takes 10 seconds to load. Moved my server to a ryzen 5 based setup and now everything is instant. I'm not sure what the limiting factor on the rpi was because the ram and cpu usage was low. Perhaps it was memory or storage speed.
It’s always run perfectly fine for me and my needs, and I even tested having shared video calling in NextCloud and it continued to work great.
I’m not sure your configuration, but it might be worth trying on a Pi4?