Default settings for the JVM

Default settings apply to the Real Time JVM when no changes are made to the environment that the JVM runs in. Common settings are shown for reference.

Default settings can be changed using environment variables or command-line parameters at JVM startup. The table shows some of the common JVM settings. The last column indicates how you can change the behavior, where the following keys apply: The information is provided as a quick reference and is not comprehensive.
JVM setting Default Setting affected by
Javadumps Enabled ec
Javadumps on out of memory Enabled ec
Heapdumps Disabled ec
Heapdumps on out of memory Enabled ec
Sysdumps Enabled ec
Where dump files are produced Current directory ec
Verbose output Disabled c
Boot classpath search Disabled c
JNI checks Disabled c
Remote debugging Disabled c
Strict conformancy checks Disabled c
Quickstart Disabled c
Remote debug info server Disabled c
Reduced signalling Disabled c
Signal handler chaining Enabled c
Classpath Not set ec
Class data sharing Disabled c
Accessibility support Enabled e
JIT compiler Enabled ec
AOT compiler (AOT is not used by the JVM unless shared classes are also enabled) Enabled c
JIT debug options Disabled c
Java2D max size of fonts with algorithmic bold 14 point e
Java2D use rendered bitmaps in scalable fonts Enabled e
Java2D freetype font rasterizing Enabled e
Java2D use AWT fonts Disabled e
Default locale None e
Time to wait before starting plug-in N/A e
Temporary directory /tmp e
Plug-in redirection None e
IM switching Disabled e
IM modifiers Disabled e
Thread model N/A e
Initial stack size for Java™ Threads 32-bit. Use: -Xiss<size> 2 KB c
Maximum stack size for Java Threads 32-bit. Use: -Xss<size> 256 KB c
Stack size for OS Threads 32-bit. Use -Xmso<size> 256 KB c
Initial heap size. Use -Xms<size> 64 MB c
Maximum Java heap size. Use -Xmx<size> Half the available memory with a minimum of 16 MB and a maximum of 512 MB c
Target time interval utilization for an application. The Garbage collector attempts to use the remainder. Use -Xgc:targetUtilization=<percentage> 70% c
The number of garbage collector threads to run. Use -Xgc:threads=<value> The number of processor cores available to the process. c
Note: "available memory" is the smallest of real (physical) memory and the RLIMIT_AS value.


© Copyright IBM Corporation 2005, 2010. All Rights Reserved.
© Copyright Sun Microsystems, Inc. 1997, 2007, 901 San Antonio Rd., Palo Alto, CA 94303 USA. All rights reserved.
US Government Users Restricted Rights - Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
This information center is powered by Eclipse technology. (http://www.eclipse.org/)