Wednesday, July 23, 2008

"free -m" on the Linux command line

One thing you can never do is over commit available RAM in the machine. If the application server fails to start and SystemOut.log contains a message like this:

JVMJ9VM015W Initialization error for library j9gc23(2): Failed to instantiate heap. 1G requested
Could not create the Java virtual machine.

Then it is highly likely that you tried to start an app server with not enough free physical RAM. Check the "free -m" command on Linux. Otherwise refer to your OS specific manuals to see how to determine how much free RAM you actually have.

1 comment:

in foo said...

i was trying to allocate 2GB for the WAS server heap size. Free physical RAM in the windows system is about 4GB ( view from taskmgr ) but still receive the same error. Total physical RAM is 6GB.

Can anyone explain that? Appreciate your advise.