The easiest way to disable unnecessary services is to uninstall them with aptitude, or whichever package manager you like. Try terminating services one by one, and see if anything bad happens. If nothing bad happens, you can probably uninstall it. On the other hand, if the system does get wonky a reboot should fix it. Or, you can research the services by name and decide whether to uninstall them. (avahi-daemon for example is a good idea to uninstall.)

To make the GUI not run, uninstall your display manager (gdm, xdm, nodm, or whatever) and uninstall your xorg server or wayland server. There may be GUI programs remaining after that, but they will only be consuming disk space, not RAM or CPU.

If the battery is old and holds little charge, you may save a few watts by removing it and throwing it away, instead of letting the system keep it topped off.

Get a power meter, such as a Kill-a-watt device. Then, experiment with different settings. If it’s consuming less than 30 watts, you’re probably fine. If you live in the US, one watt-year is about one US dollar (or a little more), so for every watt it consumes, that’s about how much you will pay per year for its electricity.

draw .io is closed source.

I cannot recommend any USB-connected drive for long-term use. (Only for portable devices that get plugged in for a little while at a time.) In the long term, any USB drive will randomly reset during periods of heavy use – including heavy writes, meaning some data will get lost.

USB enclosures tend to just crap out completely after a year or two, if used continuously on a server. I know because I twice used 1TB external drives with OpenWRT (home router) devices. The data will be safe on the drive, but you’ll have to replace the enclosure.

1. My first recommendation would be to look very carefully at the chassis and see if there’s any way at all to fit another SSD inside it. 2.5" SSD’s are usually thinner than 2.5" hard drives, so it may be possible, and most motherboards have more SATA ports than they need.

Is there possibly an NVMe slot on the motherboard? Or an open PCIe slot where you could put an NVMe adapter?

2. My second recommendation would be using a 2.5" hard drive. Newegg has a 5TB one for $135, but unfortunately that’s as large as they seem to go. It will be a bit slower than an SSD, but still probably around 150MB/s for sequential access.

3. My third recommendation, if money is really tight, would be an additional server, with a large 3.5" hard drive. This will be a lot cheaper than an 8TB SSD, but adds complexity, electricity use, space use, and possibly fan noise.

Using a VPN (like Tailscale or Netbird) will make setup very easy, but probably a bit slower, because they probably connect through the VPN service’s infrastructure.

My recommended approach would be to use a directly connected VPN, like OpenVPN, that just has two nodes on it – your VPS, and your home server. This will bypass the potentially slow infrastructure of a commercial VPN service. Then, use iptables rules to have the VPS forward the relevant connections (TCP port 80/443 for the web apps, TCP/UDP port 25565 for Minecraft, etc.) to the home server’s OpenVPN IP address.

My second recommended approach would be to use a program like openbsd-inetd on your VPS to forward all relevant connections to your real IP address. Then, open those ports on your home connection, but only for the VPS’s IP address. If some random person tries to portscan you, they will see closed ports.

So are you able to view content, but pay to download? If that’s the case, I could probably write a scraper for the site.

If you have to pay to even see the content, then you may have a bigger problem. Try pooling resources with some of your fellow students, to have one person download all the content, and then make it available to everyone else.

Another option is to expose your instructors. There’s a high probability that they are getting kickbacks, especially if this is at college level. Maybe in the form of 10% of each dollar spent by one of their students. Or, they might be getting free equipment or content from Docsity, in exchange for forcing students to use it, and offloading the costs to students.

When I was in college, one of my instructors used these “clickers” that cost students $40 per semester to rent. They used radio to allow submitting realtime quiz answers during class. Students were scored on how many questions they answered, not whether they were correct. If you didn’t pay the clicker fee, you lost that 10% of your final grade.

I was suspicious, so I looked into it. It wasn’t hard. The clicker manufacturer advertised kickbacks on their own website.