Unable to create any JVM (>1024M)

I create a simple Java file which prints something on the system开发者_JAVA技巧.out, compile and run it with the following,

public class MyClass {

    public static void main(String[] args) {
        System.out.println("MyClass here");
    }
}

java -Xmx1024m MyClass

and I get

Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.

I have 4GB memory and I have no idea at all why this would not work. Doing java -Xmx512m MyClass works, but I want to know why 1GB will be denied.

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Run your default VM with -Xms512m -Xmx1024m

The default settings are a bit low for eclipse, which is a bit of a memory hog.

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I had experienced similar problems - for me the limit was somewhere near 768M of RAM. Apparently the JVM tries to obtain a larger amount of memory, and in some cases there are limits, how many RAM can an application obtain.

If you are using a 32 bit system, but are able to use a 64 bit, use the latter, it might help. On 64 bit systems I did not encounter this error.