which OS can I use for a heap larger than 2G (linux failed)

[Christian Neuroth]

Hi there!

I am currently working on a Java app that is in need of
a huge heap (at least 4G). But as soon as I only want
to start the VM, I get the following message:

"...Error occurred during initialization of VM
Could not reserve enough space for object heap..."

This message is there each time, I try to start the VM
with more than 2G (java ... -mx2g ...)

The development machine I am working on has enough physical
memory (4G) and runs with Debian Linux. I found the following
bug:

http://developer.java.sun.com/developer/bugParade/bugs/4435069.html

So they state, it has something to do with the Linux kernel
and might be "solved" by applieing another OS.

-->>
Does anybode use a VM with larges heap space (4G and above) -
and if the answer is yes: what OS does he/ she use?
--<<

Thanks!

Christian

 

[Ben_]

-->>

Does anybode use a VM with larges heap space (4G and above) -
and if the answer is yes: what OS does he/ she use?
--<<

Solaris, for example

 

[Christian Neuroth]

Solaris, for example

and how much is possible? 4? 8? 16G?

 

[Chris Smith]

The development machine I am working on has enough physical
memory (4G) and runs with Debian Linux. I found the following
bug:

http://developer.java.sun.com/developer/bugParade/bugs/4435069.html

So they state, it has something to do with the Linux kernel
and might be "solved" by applieing another OS.

Yep, this has to do with the kernel/user boundary for the process
address space. I'm not an expert at this, so I don't know if other
operating systems divide kernel/user space differently to give user code
more address space and kernel code less. You're running into a point
here where you may want to consider using a 64-bit processor; you're
never going to be able to address *too* awfully much more RAM on a 32-
bit architecture, regardless of the operating system.

--
www.designacourse.com
The Easiest Way to Train Anyone... Anywhere.

Chris Smith - Lead Software Developer/Technical Trainer
MindIQ Corporation

 

[Roedy Green]

I am currently working on a Java app that is in need of
a huge heap (at least 4G). But as soon as I only want
to start the VM, I get the following message:

see http://mindprod.com/jgloss/jvm.html and follow the link to Marco
Schmidt's list of JVMs. Perhaps you want a 64-bit JVM. There should
be some for the Itanium and the Opteron.

With 32 bit addressing you are limited to a 4G address space, much of
which you can't use for a heap.