So I have run a minecraft server for so long, but in that time we also started multiple spawns, and additional worlds.
Pretty much no one plays on the server anymore and most of the worlds fell into archive status, so I got the idea, I never want to lose anybodies work and I like to personally just stroll around the world and find stuff someone built.

I decided to try and merge all the worlds together into one big super world. I used MCA selector to filter all the chunks that had more than a certain amount of play time and purge the rest, then afterward I copied all those chunks onto the biggest world, trying to find a decent spot on the map for them to go.

The world is still a bit of a mess but I hope that this gives me a nice base line to just continue to play it at my own pace and clean it up in game.

My plan is to go through the various spawn points and just work out and clean up the paths from place to place and peoples builds that didnt come back.

I also deleted everyones inventory, which is kind of sucky but at the same time I think if anyone does ever come back having a partial fresh start makes the game fun again. A big reason for this was players played on multiple worlds so I didn't have a good way to pick and choose which inventory to keep for the hundreds of players over the years.

Having one world instead of like 5 makes it much easier to keep up with, updating the plugins etc.
also the backups are much nicer, instead of 70gb servers now its less than 15 after the purge. all the original servers were kept the way they were but taken offline.

Oohh that sounds neat. I bet that's going to be fun to just explore all the cool stuff people built.

Sounds like some ancient civilization that abandoned suddenly their cities.

edit: what do you do about glitched chunk borders?

so I think there was some change to the way chunks are generated and it tries to merge the borders properly.
I put all the chunks in empty spots so no two different worlds shared a border, so from what Ive seen the newly created area around is smooth instead of huge cliffs like in the past.
biomes are still a bit weird, like I placed an island from one world that was in the light colored warm water and those parts stick out a bit on the dark colored water of the biome I pasted it into.
I tried to delete as much as I could of the ocean area around land before moving them over

I think this was the mesa that was pasted in but the biome was snow so it sort of merged from amplified to regular terrain and mesa to snow biome. It looks strange but not horrible I guess

Amazing.

Doesn't Minecraft now have biome blending that at least smoothens the chunk borders that would have previously resulted from this?

Yeah it did a decent job blending new unloaded chunks to ones I pasted in from older worlds.
Its still noticeable that something is off but much better than when I tried something similar a long time ago doing a half amplified half regular terrain world.

That time I just followed the ocean on where I could make my breaks roughly down the middle of the map. I forced generated all the right half if the map in amplified, deleted continents that went too far over the center and then switched the world to vanilla terrain and let people explore the non amplified to generate as they go

I added a picture of a piece in this comment
https://lemmy.today/comment/25591455