On Mon, Jun 05, 2006 at 10:48:09AM -0500, Jeremy White wrote:<br> > I am running in to some strange memory errors when trying to optimize a<br> JVM.<br> > When I set the min and max to 1.5gb and start the JVM, I immediately get
<br> an<br> > OutOfMemoryError. If I pull it back to 1.2gb or so, it works fine. The<br> > amount of physical memory in this machine is 4gb, and nothing else is<br> really<br> > running on it. The machine is running RHEL
2.1, kernel 2.4.9-e.65smp.<br> ><br> > We have another server that we just upgraded the OS on, to RHEL 3, kernel<br> > 2.4.21-40.ELsmp. On that server, the JVM starts fine with a 1.5gb min/max.<br> >
<br> > I suspect this has to do with the way the kernel manages memory. I know I<br> > have read that you can not give a JVM over 2gb of memory in Linux, but I<br> am<br> > not even getting close to that. Since this works on the newer kernel,
<br> maybe<br> > its something thats compiled in, but I was hoping it was a configuration<br> > that could be changed.<br> ><br> > Anyway, I would just like to get some ideas because I really would like to
<br> > know more about tuning the kernel for memory management, and I would like<br> to<br> > know why these JVMs are throwing these errors - mostly out of curiousity<br><br>- Ignored:<br> as<br> > to how things work.
<br><br> What JVM and what version? Have you tried SUN, IBM and JRockit?<br><br> Is this for an application server, or a J2SE application?<br><br> From the memory limits I infer you are running on i386. Are both<br>
machines identical? Are both JVMs indentical?<br><br> florin<br><br> Florin,<br><br> Thanks for the quick response. I am currently using the Sun JVM version<br> 1.4.2_08. This is for a Tomcat application server version
4.1.31 . Yes<br> both machine are identical except for the OS. One is RHEL 3, kernel<br> 2.4.21-40.ELsmp and the other is RHEL 2.1, kernel 2.4.9-e.65smp.<br><br> Jeremy