Luanti Server Performance Tuning
Luanti is efficient compared with many other sandbox servers, but large explored worlds, active mods, and aggressive map generation can still drag the server down. The goal of tuning is to keep the server step stable, reduce avoidable mapgen spikes, and stop one player or one machine-heavy build from dominating the whole instance.
1. Measure server lag before changing settings
Start by separating client-side complaints from real server slowdown. Low FPS on one player's machine is not the same thing as a server that cannot keep up.
Watch the server logs for slow steps and warnings, especially messages that show the server taking much longer than its normal update interval. If the server step is consistently high, the problem is real and global.
2. Reduce map generation spikes
Fresh terrain generation is one of the most expensive things the server does. The farther players spread and the faster they force unexplored terrain, the more CPU time mapgen consumes.
nano ~/.luanti/luanti.conf
Useful settings to review:
max_block_generate_distance: lower values reduce how far ahead the server tries to generate terrain.max_simultaneous_block_sends_per_client: helps prevent one fast-moving player from flooding the server with chunk requests.num_emerge_threads: lets map generation use extra CPU threads when the host has room for it.
Do not raise all of these blindly. Tune them against the actual CPU and player behavior you see on the server.
3. Control active world simulation
A Luanti server gets expensive when too many active blocks, mobs, or dropped items stay alive around too many players at once. This is where modded survival worlds start to hurt.
active_block_range: lower it if too much machinery or mob logic is running at once.max_objects_per_block: prevents one area from filling with a destructive number of active entities.item_entity_ttl: shorter item lifetime reduces junk accumulation after fights, mining, or explosions.
If your players build mob farms, large redstone-like logic networks, or automated sorting systems, these settings matter a lot more than raw RAM.
4. Profile the mods instead of guessing
If the base settings look reasonable and the server is still slow, profile the mod stack. A single badly behaved mod can matter more than ten well-behaved ones.
/profiler print
/profiler save
Use the profiler output to find the real offender. If one mod dominates runtime, fix that specific mod, adjust its settings, or remove it before touching unrelated parts of the server.
5. Watch storage and backend choice
World storage is another common bottleneck. SSD or NVMe storage helps more than many new operators expect, especially on busy public worlds with a lot of exploration and writes.
SQLite is fine for many private or small public servers. If your world is large, heavily explored, or hammered by many concurrent writers, PostgreSQL can be the better long-term backend. Make that move carefully, on a backup, and test the migrated world before reopening it to players.
6. Practical performance checklist
- Confirm the slowdown is real server lag, not only one player's client problem.
- Review mapgen settings first if players are forcing new terrain constantly.
- Lower active-world simulation if mobs, machines, or dropped items are out of control.
- Use the profiler to identify heavy mods before making broad changes.
- Check storage speed and backend choice if writes are becoming a bottleneck.
Want tuning without hand-editing every setting? Supercraft's Luanti Server Hosting is the cleaner path when you want backups, fast storage, and safer defaults for public or modded worlds.