2025-09-14T23:24:00+09:00

Claude Code: updating an Ubuntu 24.04 Minecraft server and JVM settings for about $1

I used Claude Code to update a Minecraft server on Ubuntu 24.04 and adjust its JVM startup settings with Aikar's Flags. This records the low-cost experiment, including connection testing and the limits of what I verified.

I updated my home test server running Ubuntu 24.04.

It also hosts a Minecraft server.

I decided to try Claude Code for the update and optimization.

Claude Code is an agentic coding tool that runs in the terminal.

Put simply, it is AI operating inside Ubuntu's terminal.

About Claude Code:

https://docs.anthropic.com/ja/docs/claude-code/overview

Installation was straightforward, so I will skip the details. I opened the API console. The starting balance was $12.12. After installing Claude Code on Ubuntu 24.04, I started it by entering claude. In the terminal, I asked in Japanese, roughly, "Please update the system." It analyzed the current setup and proposed updating the Minecraft server. Interesting. It asked for permission to proceed at various points. Entering 1 meant Yes. It also made a backup before working, which was reassuring. It appeared to be downloading the latest Minecraft server. There was an error, perhaps because the file was not at that location. AI tools often seem weak at identifying the exact location of files on the web. It eventually found and installed the file, and adjusted configuration files too. Minecraft server startup accepts options such as memory allocation. Claude Code supplied a whole collection of them. I was still wondering what that error had been. Then the work was finished. Here is the report.

It had performed the update and made some improvements.

I looked up what Aikar's Flags were.

Apparently, Aikar's Flags are a set of Java Virtual Machine (JVM) startup arguments tuned specifically to optimize Minecraft server performance.

That was useful to learn.

That explained the long list of options. Instead of setting equal minimum and maximum values such as java -Xmx4096M -Xms4096M, this setup left a gap between them: -Xmx6144M -Xms2048M. I understood this as allowing dynamic memory allocation to use memory efficiently according to server load. It also tested startup. I then tried connecting with the latest version available for this test, 1.21.8. The connection worked. Excellent. I asked it to remove the backups and explain what it had improved. Now for the API cost: the balance went from $12.12 to $11.34, so roughly a dollar, or about ¥150. The work took around 30 minutes. Compared with an hourly rate, that is cheap; I even thought it would be cheaper than hiring someone in India. Through a conversation with Claude Code, I updated the Minecraft server and verified that I could connect. It cost about a dollar. I have not confirmed the validity of every individual configuration change, so I am recording this as a functional test on my home test server.