Chunky: Size Your Pregeneration Job Before Launch

Choose a Chunky pregeneration area by working backwards from your opening deadline: define the playable area, measure a representative trial, and leave time and disk space for the final backup and rehearsal. A radius copied from another server tells you very little about whether your world will be ready.

This guide is for community operators and event teams preparing a Java world with Chunky already installed. Its output is a small capacity worksheet and an opening decision. The numbers below are invented examples, not Mineando benchmarks or a promise about your hardware.

Turn the playable area into a generation budget

Write down the required world, centre, shape and playable extent. Include tournament destinations, portal exits and any teleport locations used by your event. Record each dimension separately: an overworld estimate does not establish the cost of preparing a modded dimension.

Check your units before approving the scope. A plain Chunky radius is in blocks; the vanilla world border uses a diameter and is square. A border size of 6,000 therefore means a half-width of 3,000. See the official radius reference and world border guide.

For a first geometric estimate, a square with half-width r covers approximately (2r / 16)² chunk columns; a circle covers approximately πr² / 256. These are area calculations, not exact counts from Chunky. Edge alignment, existing terrain and generation outside the selected footprint can change the work and storage involved.

Selected footprint	Approximate chunk columns
Square, half-width 1,500 blocks	35,156
Square, half-width 3,000 blocks	140,625
Circle, radius 3,000 blocks	110,447

Doubling the radius quadruples the area. A circle saves area compared with the enclosing square, but leaves its corners uncovered. Do not choose it merely to improve the estimate if the event needs those corners.

Treat the playable boundary and the generation selection as two settings to verify. Decide whether your routes need prepared terrain beyond the playable edge for their viewing distance. Any additional margin belongs in the estimate; there is no universal margin that this article can certify for your setup.

Measure a trial that resembles the final job

Before generating a production world, retain a recoverable backup and agree who can stop the work. If your team has never restored its complete setup, use the backup restore rehearsal to establish that procedure first.

Use the intended Minecraft version, world generator, datapacks, mods and relevant configuration for the trial. Keep its resource allocation comparable to the planned generation environment. Removing a world-generation dependency to make a test faster invalidates the estimate for the original world.

Pick an area containing new terrain and representative structures. Record start and finish times, processed chunks, free disk space before and after, and any errors. Repeat across another representative area if the world has substantially different terrain. Include a trial long enough to expose sustained storage pressure; a short burst immediately after startup is weak evidence for an overnight job.

Chunky reports progress, generation rate and an estimated remaining time. Its pregeneration guide explains those fields. Record several observations, rather than treating the first ETA as a delivery commitment.

Existing chunks are skipped, according to the Chunky FAQ. A trial mostly traversing old terrain can therefore look misleadingly fast for a new world. Keep new-terrain measurements separate from scans of existing areas.

Calculate a range, then reserve operating time

Suppose your planning worksheet assumes a sustained rate between 40 and 60 new chunks per second. This is a hypothetical input that you must replace with observations from your environment.

For the square with half-width 3,000:

• At 60 chunks per second: 140625 / 60 / 3600 ≈ 0.65 hours.
• At 40 chunks per second: 140625 / 40 / 3600 ≈ 0.98 hours.

For half-width 6,000, the approximate count becomes 562,500 and the same assumed rates imply about 2.60–3.91 hours. These estimates cover generation work only. They exclude backup completion, restart, file transfer, map rendering, faults and rehearsal.

If the available maintenance window is three hours, the larger square already exceeds it at the slower assumed rate. Even the smaller square needs a separate allowance for the remaining tasks. Do not reserve the entire window for generation and then discover that the backup cannot finish before participants arrive.

Make the fallback explicit before starting: reduce the opening area, defer an optional dimension, or move the opening time. Name the person who can approve that change and the latest decision time. A larger machine is another project decision requiring a new measurement, not an automatic fix.

Budget disk space independently

Use the change in world storage during the trial as a local observation. If, hypothetically, 10,000 newly generated chunk columns add 1 GiB, a simple proportional estimate for 140,625 columns is about 14.1 GiB. That is an illustrative calculation, not a standard Minecraft storage ratio.

It excludes existing data and assumes the sample remains representative. Different dimensions, structures and world generators can invalidate that assumption. Measure the same storage quantity each time; do not mix apparent file size with allocated disk usage.

Also reserve space for the backup destination if it shares the disk, temporary copies, logs, rendered maps and subsequent player activity. Set a free-space threshold at which the operator pauses the job. Choose that threshold from your actual operating requirements, not a percentage copied from this example.

Make an opening decision from evidence

Before the agreed cutoff, complete a short handover record:

• The exact software set and selection that finished, including every required dimension.
• Actual elapsed time and remaining free space, with errors or incomplete tasks listed.
• A completed backup and checks of the spawn, event routes, portals and boundary.
• A rehearsal with the intended gameplay, plus the person accepting any limitations.

Pregeneration completion alone does not establish player capacity: entities, plugins, network conditions and the event mechanics still need their own rehearsal. A server can have prepared terrain and still perform poorly when the actual activity begins.

For a commissioned setup, send this worksheet, the opening date and the intended gameplay to Mineando’s managed infrastructure service. Generation preparation, monitoring, backup procedures and rehearsal responsibilities can then be scoped for the project. Paid work is quoted individually; ongoing support and live coverage are agreed separately.