On a Redhat CentOS 6.4 are only a few process running, using about 3GB RAM (System has 12GB available). One of the processes is a WSO2ESB Server (java), we start it with those parameters:
After a while we get an OutOfMemory Exception, but the java process(WSO2ESB) process is not even using its 3GB. In the jconsole you can also see that those parameters where set correctly (Linux Server has about 9GB free RAM at this point)
Does Linux not give us the configured 3 GByte RAM?
On a exactly same Windows Installation - the java process can use it's 3GB Ram without any issue.
Screenshot of the jconsole showing the heap memory usage only between 0.3 and 1.0 GB. At moment of OutOfMemory exception Heap memory was at 0.5GB, but the process would have 3GB to work with, but it doesn't...
EDIT: added log of java process:
java.lang.OutOfMemoryError: unable to create new native thread
EDIT2: added free -m output: