Chunky pregenerates chunks very quickly and efficiently, which is helpful for reducing server lag.
Check out the Installing Fabric Mods page.
While you will normally notice a significant boost in server performance after you are done pregenerating your chunks, the process is quite intensive, and you may see server lag while generating. Generating large maps can also use a lot of storage space.
To start generation, you should first select a world and a radius by using
chunky world <world>, and then
chunky radius <radius in blocks>.
After that, you can run
chunky start to start the generation.
It's normally good to enforce this pregeneration with a world border so that people don't generate new chunks and cause more lag. It's also good to increase the radius of Chunky by ~ 256 blocks (16 chunks) so that you have some buffer when people are right next to the border.
If you wish to pause or cancel the pregeneration, you can run
chunky cancel or
To continue pregeneration after you've paused it, run
You can use the table below to estimate the file size of your world after you generate it. The values below are for 2k by 2k blocks (1k radius).