Direct answer
Leaf’s optional LINEAR region-file format differs from the default Anvil/MCA format and uses different compression/storage behavior. Leaf docs warn that it is experimental and risks chunk-data loss.
How to check it
- Back up the complete world to separate storage, test the conversion on a copy and check the exact release’s region format settings and conversion procedure.
- Record the original configuration or test conditions, capture a profile or a repeatable observation, and identify the affected world or player group.
- Make the measurement under the same player count and workload you will later use to verify the change.
What to change
Do not switch a production world to LINEAR just to save disk space; test save/reload integrity and the ability to recover a backup to an MCA-compatible build first.
World-file format is a data durability decision, not a safe quick fix for ordinary high MSPT. Retain backups before each migration step.
Software and version notes
Before using any example, confirm that your exact server build exposes this option and that a per-world override does not take precedence. Leaf examples from publicly available 1.21.1 documents are historical; do not assume the same keys or defaults apply to later builds.
This article is written for Leaf. Configuration keys and defaults can move between versions. The source material checked for this page includes Leaf project repository. If your server is Folia, Leaf, Purpur, Fabric, Forge, NeoForge, or another fork/loader, do not assume a Paper-only setting exists or behaves identically.
Verify the result
Repeat the same test with the same software build, player count and world activity. Compare the targeted symptom and any spark measurements, then check that intended game mechanics still work. If the change does not produce a reproducible improvement, revert to the recorded baseline.