JBoss 4.2.3 errors

[kumarranga]

What would be the maximum memory I can have in JBOSS 4.2.3 ?

My current settings are:
JAVA_OPTS="-Xms1024m -Xmx2048m -XX:PermSize=384m -XX:MaxPermSize=512m"

If I increase the permsize and/or maxpermsize, i am getting error on startup:
===================================
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
+++++++++++++++++++++++++++++++++++

I have a 4GB RAM on the server. Any suggestions are appreciated.

[peterj]

If you have 32-bit OS and/or are running a 32-bit JVM, you can use at most around 1.7GB for both the max heap size plus max permgen. The actual maximum depends on the OS, and the version of the OS.

See this: http://www.jboss.org/index.html?module=bb&op=viewtopic&t=154475