Re: How much heap can I reserve for JVM? Error when allocation very much heap

From:

Lew <noone@lewscanon.com>

Newsgroups:

comp.lang.java.help

Date:

Sun, 11 Apr 2010 16:39:31 -0400

Message-ID:

<hptc23$6t3$1@news.albasani.net>

Raymond Schanks wrote:

When I call a 1.6 Java program (under WinXP) with a command like:

java -Xms5m -Xmx1200m -jar myapp.jar

Then I get errors like:

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

Why ? I have 2 GB physical memory.
Even if I would allocate more heap than physical memory then JVM should use the swap file
to put the additional heap on hard disc.

Am I right?

How can I avoid the errors above (of cause without decreasing the value) ?

Your "-Xms" value is too small. Give it something reasonable like 64m or
128m. I think I heard somewhere that the VM has problems when "ms" is too small.

Regardless of what else was said in this thread, 1200 MB is within the range
that you should be able to allocate on a 32-bit Windows platform.

There is one reference from 2006 at bugs.sun.com that blames something similar
on a Windows 2003 Server bug:
<http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6474166>
"11-Closed, Not a Defect"

Similar problems in Linux in the past have used the 'ulimit' command as a
solution to allow the OS to allocate more heap.

--
Lew