I have a program Vuze that is written in Java, which I use to download very large files, and I'm having a problem with it. I need to increase the amount of memory it uses. I've followed the directions for the application but it doesn't change the real memory usage. This would then be because Java (JVM) is not set to support the amount of memory I set in the application.

I both get errors about files missing and low memory.

How can I increase the memory used by my Java Virtual Machine?

My Java is Oracle. My system is Fedora 20 X86_64 KDE.