Which services on the Pi are mandatory and optional?

Question

I am looking to make the Pi more responsive by disabling unneeded service. I am looking to disable services in /etc/init.d (and anywhere else if there are other places) and want to find a list somewhere that details all the services that are optional so I can disable it. Or can anyone give me a list of unneeded services?

Where can I find such a list? Raspbian stretch is what I'm using.

Answer 1

Your question isn't easy to answer. it depends on what you want to have running. "Raspbian Buster Light" will have a much smaller list of mandatory services than "Raspbian Buster with desktop and recommended software". And no, I haven't seen a list of needed services for this installations. I think all running services are needed to have a stable operating system for what it is setup. You can find all running services with:

rpi ~$ systemctl

Another way to strip down an installation is to setup a system with debootstrap. This is a tiny Raspbian installation only with essential programs and services to have a minimal running system. Here you can be sure that you only have mandatory services running. Then you can install step by step what you want and control what additional services you want. How to do it look at Install base Raspbian from repository, not using an image.

Answer 2

Rather than check an existing list, I'd suggest running service --status-all and looking at what's already running. Installs take on a life of their own after you've been using them for a while. Some of the listed services you'll probably recognize. The rest are easy enough to Google and work out if you need it.

Checking my own service list, which is from a somewhat out of date Jessie Lite install, there's not much I'd suggest disabling. Maybe dhcpcd/ifplugd/networking/ssh/wicd if you didn't use networking, but that's it. I think Rasbian already fairly trimmed down.

Another option would be to use a package manager like aptitude to see what's installed, which includes descriptions, and remove those packages you don't need.

Answer 3

If you want Raspbian with just the necessary services, start with a download of Raspbian Buster Lite 2019-09-26 from https://downloads.raspberrypi.org/raspbian_lite_latest

Then add in any pieces that are missing that you need to run your server.

You can find the things that delay boot time (usually networking) with systemd-analyze and systemd-analyze blame commands.