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Hi,

I am using IBM WebSphere 5.1 which is using IBM JDK 1.4.1.

When I set the max heap size of WebSphere to 2048M,
the message

<GC: Reduced max java heap size to 1687289856 bytes due to memory
contraints>

was logged in the native_stderr.log.

The server is windows based, and have 3G physical memory.

Could you tell me why there is 1687289856 bytes constatins?
and is it possible to solved by adding more physical memory?

thanks!

In article < .com>,
"Leon" <> wrote:

> Hi,
>
> I am using IBM WebSphere 5.1 which is using IBM JDK 1.4.1.
>
> When I set the max heap size of WebSphere to 2048M,
> the message
>
> <GC: Reduced max java heap size to 1687289856 bytes due to memory
> contraints>
>
> was logged in the native_stderr.log.
>
> The server is windows based, and have 3G physical memory.
>
> Could you tell me why there is 1687289856 bytes constatins?
> and is it possible to solved by adding more physical memory?
>
> thanks!

It's a limitation of Windows systems that they can not give more than
approximately 1.6GB of memory to Sun's JVM. The solution is to use a
real operating system and not Windows.
--
Steve W. Jackson
Montgomery, Alabama

Like the OP said it's a limitation inherent to the Windows platform.

See http://www.unixville.com/~moazam/2004/06/03.html and
http://www.unixville.com/~moazam/ for example.

AFAIK, more RAM won't help and the /3GB switch either.