Big problem chunk corrupt huge lag.

Hello to you, today I have a big big problem on my server.
Following insufisant disk space, it is stopped on its own (without the / stop restarting the server physically).
So, from that day, it really lag, the console is flood of messages:

15:29:56 [INFO] Chunk (-20, -6) stored at (-10, -7)
15:29:56 [INFO] net.minecraft.server.Chunk
15:29:56 [SEVERE] java.lang.Throwable
15:29:56 [SEVERE] at net.minecraft.server.ChunkProviderServer.getOrCreateChunk(ChunkProviderServer.java:120)
15:29:56 [SEVERE] at net.minecraft.server.World.getChunkAt(World.java:213)
15:29:56 [SEVERE] at net.minecraft.server.World.b(World.java:1733)
15:29:56 [SEVERE] at net.minecraft.server.World.getEntities(World.java:838)
15:29:56 [SEVERE] at net.minecraft.server.Entity.move(Entity.java:391)
15:29:56 [SEVERE] at net.minecraft.server.EntityLiving.a(EntityLiving.java:570)
15:29:56 [SEVERE] at net.minecraft.server.EntityLiving.u(EntityLiving.java:676)
15:29:56 [SEVERE] at net.minecraft.server.EntityMonster.u(EntityMonster.java:30)
15:29:56 [SEVERE] at net.minecraft.server.EntityLiving.p_(EntityLiving.java:231)
15:29:56 [SEVERE] at net.minecraft.server.EntityMonster.p_(EntityMonster.java:34)
15:29:56 [SEVERE] at net.minecraft.server.EntityCreeper.p_(EntityCreeper.java:57)
15:29:56 [SEVERE] at net.minecraft.server.World.entityJoinedWorld(World.java:1007)
15:29:56 [SEVERE] at net.minecraft.server.WorldServer.entityJoinedWorld(WorldServer.java:52)

What to do?
I breakdown, my players are complaining, without stopping the server crashes I haveto stop the closing process and I did not backup before (except for 7 days).

Thank you very much much in advance to those who can save me!

Sorry for my English, I'm French.

 

Okay, first you need to find out where the two chunks are.

What I did was use worldedit's chunk info tool to find out the ID (-20, -6) etc.
Mark out the borders of the chunks using the //walls command

Then go into MCEdit (A map editing tool) and use the chunk control tool to generate new chunks. They'll be empty, so clone a chunk from elsewhere to fill the gap.

I saved my map that way.

 

@Niteaw @PsychoNecrosis Or you could use Chunkster, which is designed to fix this exact problem

 

Hello, first of all I really really want to thank you both.
I used your software to repair the chunk, it has found a lot of mistakes he correctedand the console does not seem to flood it.
The lag does not seem to come, but for now is that we both connected to the server.
I will keep you up to date on there will be more people connected to the server

Again thank you, you're great!