I need to collect logs of garbage collection information for a GlassFish 2.x server. Simply using VisualVM or another such tool is inadequate, because I need to collect information over an extended period of time rather than one sitting. In all my searching on this question, the consensus is that you add the following JVM options: -verbose:gc -XX:+PrintGCTimeStamps -XX:+PrintGCDetails In the GlassFish Admin Console, I go to... Configurations->[my cluster name]->JVM Settings->JVM Options ... and use the "`Add JVM Option`" button to add three new options matching the list above. However, I never see any GC logging anywhere. There's nothing in the "`jvm.log`" or "`server.log`" files for my domain... and when I start my domain using the "`--verbose`" option, no GC info ever shows up in the console output either. I have checked the "`domain.xml`" file for my domain, and it appears that the GlassFish Admin Console ***IS*** writing those three options. Just for giggles, I tried adding a fourth "`-Xloggc:/tmp/gc.log`" option, so I would *know* where the logged information is supposed to go... but that file is never created either. Am I missing something really obvious here?