how to set maximum heap size in jboss-4.2.3.GA?

[suman gayakwad]

I got 4gb of RAM. If i tried to set JAVA_OPTS to 2048m (ie. set JAVA_OPTS=%JAVA_OPTS% -Xms512m -Xmx2048m)

I am getting the following error

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


Any suggestions on how to increase the heap size ?

Thanks in Advance

[Mark Spritzler]

It depends on your OS. If you have a 32 bit OS, then the max you could set it to is 2gb.

Also note that you kept the min to 512M, normal practice is to keep the min and max the same, so try -Xms2g -Xmx2g

If that doesn't work, then go with 1900 on both.

If this is a production box, then you might consider having two instances running on the same machine so you don't waste the extra 2GB ram you have in the box.

Mark

[Peter Johnson]

Which OS are you running? If Windows, the maximum heap size you can specify is around 1.7GB (though just now trying it I needed to get -Xmx down to 1500M before it would run).

Apparently, the JVM verifies that it can allocate the maximum heap size before it runs, so you must set the maximum to a small enough value to fit within the process' address space.