There is insufficient memory for the Java Runtime Environment to continue.

1. What OS are you using:
Linux Centos-5
2. What architecture is the OS you are running:
x86
3. What version and architecture is your java install?
java version "1.6.0_25"
Java(TM) SE Runtime Environment (build 1.6.0_25-b06)
Java HotSpot(TM) Server VM (build 20.0-b11, mixed mode)
4. Are you running any wrappers? McMyAdmin, mcadmin, Hamachi, etc?
VPS
5. What build of CraftBukkit are you running?
Craftbukkit version git-Bukkit-0.0.0-766-g3fc0460-b818jnks (MC: 1.6.6)
6. What command are you using to run your CraftBukkit server?
java -Xms1536M -Xmx1536M -jar craftbukkit.jar nogui
7. What plugins are you running?
So many plugins that I use:

8. What error are you getting?
This error isn't appearing on server.log, only in my console:

The hs_err_pid3104.log:

9. What have you tried already?
I think - nothing. Don't know what to do. And this is madness! It's so annoys me, because it happening every other 1 or 2 hours. Before was everything OK and I didn't changed anything.

Mine VPS: 2048MB CPU Intel i7 ~4600MHz using putty to connect

 

You're apparently out of RAM. You might want to try cutting down on plugins, processes, or adding more to the machine. The error says it cant allocate 1 MB of RAM to a chunk.

 

And if I raise VPS RAM to 2560MB and run craftbukkit on 2048MB, will this fix the problem?

 

Worth the try.

Edit: If your paying to add RAM, I would wait. I'm only trying to troubleshoot, not cost you money. I don't know if it will fix it.

 

I can't delete plugins, they all are necessary for server and in future I will only add them more. No more processes are working in the same time when server is on except java, but it's necessary too.

 

Try removing a few plugins to see if you can get rid of the error. Its just temporary, so remove the bulkiest ones you can.

 

will try and I suspect that this happening when more players (12<) are playing at the same time, but how I mention that this didn't happened before, must to remember what was the last plugin I added when this ** started to happening.

 

I'm getting the exact same problem, only I'm running a CentOS 5.5 rather than 5.0.
Perhaps it's a problem with the OS? I don't know..

 

It's the only problem in low RAM, now I have 3GB ram and problem disappeared.