Java – Problem with monitoring Glassfish with JConsole

You are presumably using different garbage collectors. The name of the PermGen memory area is different depending on the selected garbage collector:

• -XX:+UseParallelGC : PS PermGen
• -XX:+UseConcMarkSweepGC : CMS PermGen
• -XX:+UseSerialGC : PermGen

Looks like Tomcat is started up with either the serial ( stop-the-world ) collector or the parallel collector.

Verify any inconsistencies in the startup scripts or the environment settings.

Update: The garbage collector and memory settings are influenced by the JVM ergonomics , which means that they get auto-selected at startup based on the characteristics of the computer the JVM is running on. I can't find any references right now but IIRC they are based on CPU architecture and total memory available.

I suggest you specify one of the garbage collectors in your startup scripts. Depending on your application, it might not be good to have a random garbage collector picked.

The error you've got means that JVM couldn't claim enough memory to start. It is possible that mmap call fails in VPS, though you have lots of free memory reported by system, due to memory overcommit mechanism.

Xmx option to JVM is an upper heap memory limit. You may need to tune it, but it should not prevent glassfish from starting. What you need is Xms option. It is 128Mb by default, try to reduce it first.