Quoting Jeremy White <jwhitenews at gmail.com>:

> I am running in to some strange memory errors when trying to optimize a JVM.
> When I set the min and max to 1.5gb and start the JVM, I immediately get an
> OutOfMemoryError. If I pull it back to 1.2gb or so, it works fine. The
> amount of physical memory in this machine is 4gb, and nothing else is really
> running on it. The machine is running RHEL 2.1, kernel 2.4.9-e.65smp.
>
> We have another server that we just upgraded the OS on, to RHEL 3, kernel
> 2.4.21-40.ELsmp. On that server, the JVM starts fine with a 1.5gb min/max.
>
> I suspect this has to do with the way the kernel manages memory. I know I
> have read that you can not give a JVM over 2gb of memory in Linux, but I am
> not even getting close to that. Since this works on the newer kernel, maybe
> its something thats compiled in, but I was hoping it was a configuration
> that could be changed.
>
> Anyway, I would just like to get some ideas because I really would like to
> know more about tuning the kernel for memory management, and I would like to
> know why these JVMs are throwing these errors - mostly out of curiousity as
> to how things work.
>
> Thanks you in advance fro your help.
>
> Jeremy


What JVM are you using?

What arguments are you passing to the JVM?

What is the error (specifically) that you are seeing?

I've not heard about a 2Gb limit with JVM's before, that could be 
something from prior to 1.4 Java, or it could be that I've just not 
heard of it before.

Thanks,
Josh