Identifying lost physical memory

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http://stackoverflow.com – I am having issues with a server running out of physical memory and I'm having troubles discerning whether it is from my application's Java process or something else on the server. Let's take the following scenario: Server physical memory: 3747MB Java -Xms64m Java -Xmx512m Java XX:MaxPermSize=512m When I boot up the server, the OS (RHEL) reports that 487MB are being used, using your favorite memory reporting tool (top, cat /proc/meminfo | grep Mem, free -m, etc). When I start my Java process (pid 123), it uses around 215MB of physical memory (as reported by RES memory in ps -f -p 123), takin (HowTos)