Chunk and region problems - Fenixin/Minecraft-Region-Fixer GitHub Wiki

Here you will find a small explanation of all the problems region-fixer can detect.

Chunks problems

Corrupted

Chunk inside a region-file are stored compressed. A corrupted chunk is a chunk that can't be decompressed anymore (usually a CRC error).

Solution: Once a chunk is corrupted can't be decompressed and it's lost. When minecraft finds a chunk like this it will silently delete it a regenerate it. Region-fixer can automatically replace it using a backup or delete it.

Wrong located

The region file has a header and in there is where it's written where the chunks are in the minecraft world. But inside the chunks there is also two coordinates with the same information. Sometimes these coordinates doesn't match, and when this happen, the server will complain about a wrong located stuff.

Solution: This chunks can be read. Region-Fixer can remove them or replace them using a backup, extacly the same way as is done with corrupted chunks. This chunks can be much better fixed but for the moment is not implemented.

Too many entities problem

This is not a problem by himself, is not like a corrupted chunk or a wrong located chunk. This problem happens when there is a lot of entities in the same chunk. Although it doesn't look like a problem, the server has to move all the entities in every in game tick. This can make the server lag or even make it non working (when the amount of entities is really big... thousands).

Solution: Region-Fixer can delete all the entities in that chunk. Please note that entities are things like items in the ground (no in chests or users), mobs, animals... etc. See http://www.minecraft...net/wiki/Entity to know all the things that entities are.

Sharing offset

Region files are like small file systems. A region file has a header (like the index in a book) where it stores where all the chunks are. Sometimes, in the region file herader there are two (or more) headers pointing to the same chunk (with the book, two chapters that are in the same pages) and this is not good.

Solution: One of the chunks, is not really there, it jus has a reference in the region header. The solution is to remove the false reference from the region header.

Missing 'Entities' TAG

In the last bug reports chunks missing the mandatory TAG 'Entities' have been found. Region Fixer can now detect this chunks. Note that It doesn't check for any other mandatory tags in the NBT structure right now, though it seems that a lot of mandatory tags could be missing.

If you want to know more please, see issue #75

Solution: Region fixer can remove this chunks or create the missing NBT structure.

Region problems

Too-small region file

It's a region file that it's so small in size that it doesn't have space to store the header. Any region file smaller than 8KiB is considered 'too-small'.

Solution: Removing or replacing it with a backup are the only real solutions. The region file has almost no info in it, I would say it's not even a region file!

Unreadable

This mean that region-fixer couldn't acces to this region file. Althoug infrecuent there are a lot of causes for this: file permission, bad file system, IOErrors in the disk, etc...

Solution: There's no solution from Region-Fixer point of view. It can't acces the file! Look by yourself what is going wrong.

Unreadable 'Permission Error'

This mean that region-fixer couldn't acces to this region file but in this case the problem is premission related. That means that you don't have the requiered permission to open the region file as read and write. Please, note that Region Fixer always open the region files as read+write. If you don't have write persmission to write in some region files they will be asigned this status.

Solution: There's no solution from Region-Fixer point of view. It can't open the file! Look by yourself what is going wrong.