Home > Archive > EAserver > March 2005 > Increasing Available Memory for EAServer on Windows









You are viewing an archived Text-only version of the thread. To view this thread in it's original format and/or if you want to reply to this thread please [click here]

 

Author Increasing Available Memory for EAServer on Windows
Jonas Olsson

2005-03-30, 7:08 pm

http://www.sybase.com/detail?id=1028806

This article describes a way to enable EAS 5.x to address
more than 2Gb of memory under Windows. Can anybody
confirm/deny that this also increases the memory available
to the JVM?
It is generally reported that the Sun JVM has a built-in
issue with memory above ~1,6Gb due to discontinous memory
areas, but I know EAS has it's own (?) Heap Manager so
perhaps that explains why it can move past this limit.
James

2005-03-30, 7:08 pm

I assume this only applies with the /3GB switch for Windows
in the boot.ini.

With this switch Windows allows 3GB application space and
1GB shared kernal space, compared with normally 2GB app
space and 2GB kernal space.

Reading the Microsoft web site on this switch it will also
only apply to EXE's which have a bit set inside them. Which
is what I would assume this article sets. Java does not
have this switch, so cannot access more then 2GB, which
drops to <1.6GB due to the System DLL's being in the way.

Since Windows only allows a maximum of 3GB application
space, I cannot see how Jaguar can access more then this.

Unless on a 64bit Windows install.

Has anyone set this switch and tried running EAS as per this
article ?


> http://www.sybase.com/detail?id=1028806
>
> This article describes a way to enable EAS 5.x to address
> more than 2Gb of memory under Windows. Can anybody
> confirm/deny that this also increases the memory available
> to the JVM?
> It is generally reported that the Sun JVM has a built-in
> issue with memory above ~1,6Gb due to discontinous memory
> areas, but I know EAS has it's own (?) Heap Manager so
> perhaps that explains why it can move past this limit.

Jonas Olsson

2005-03-30, 7:08 pm

But the JVM is started from within jagsrv.exe. Could it
benefit from the bit in this way?

/jonas

> I assume this only applies with the /3GB switch for
> Windows in the boot.ini.
>
> With this switch Windows allows 3GB application space and
> 1GB shared kernal space, compared with normally 2GB app
> space and 2GB kernal space.
>
> Reading the Microsoft web site on this switch it will also
> only apply to EXE's which have a bit set inside them.
> Which is what I would assume this article sets. Java does
> not have this switch, so cannot access more then 2GB,
> which drops to <1.6GB due to the System DLL's being in the
> way.
>
> Since Windows only allows a maximum of 3GB application
> space, I cannot see how Jaguar can access more then this.
>
> Unless on a 64bit Windows install.
>
> Has anyone set this switch and tried running EAS as per
> this article ?
>
>
> this limit.

Sponsored Links





Also available: Server administration forum archive | Web Design forum archive | Software forum archive | Hardware reviews archive | Programming forum archive

Copyright 2008 droptable.com