settings for the JVM

Default settings for the JVM

This appendix shows the default settings that the JVM uses (how the JVM operates if you do not apply any changes to its environment). The tables show the JVM operation and the default setting.

The last column shows how the operation setting is affected and is set as follows:

• e - setting controlled by environment variable only
• c - setting controlled by command-line parameter only
• ec - setting controlled by both (command-line always takes precedence) All the settings are described elsewhere in this document. These tables are only a quick reference to the JVM vanilla state

For default GC settings, see the following table:

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

JVM setting	AIX®	i5/OS®	Linux®	Windows®	z/OS®	Setting affected by
Default locale	None	None	None	N/A	None	e
Time to wait before starting plug-in	N/A	N/A	Zero	N/A	N/A	e
Temporary directory	/tmp	/tmp	/tmp	c:\temp	/tmp	e
Plug-in redirection	None	None	None	N/A	None	e
IM switching	Disabled	Disabled	Disabled	N/A	Disabled	e
IM modifiers	Disabled	Disabled	Disabled	N/A	Disabled	e
Thread model	N/A	N/A	N/A	N/A	Native	e
Initial stack size for Java™ Threads 32-bit. Use: -Xiss	2 KB	2 KB	2 KB	2 KB	2 KB	c
Maximum stack size for Java Threads 32-bit. Use: -Xss	256 KB	256 KB	256 KB	256 KB	256 KB	c
Stack size for OS Threads 32-bit. Use-Xmso	256 KB	256 KB	256 KB	32 KB	256 KB	c
Initial stack size for Java Threads 64-bit. Use: -Xiss	2 KB	N/A	2 KB	2 KB	2 KB	c
Maximum stack size for Java Threads 64-bit. Use: -Xss	512 KB	N/A	512 KB	512 KB	512 KB	c
Stack size for OS Threads 64-bit. Use-Xmso	256 KB	N/A	256 KB	256 KB	256 KB	c
Initial heap size. Use -Xms	4 MB	4 MB	4 MB	4 MB	4 MB	c
Maximum Java heap size. Use -Xmx	Half the available memory with a minimum of 16 MB and a maximum of 512 MB	2 GB	Half the available memory with a minimum of 16 MB and a maximum of 512 MB	Half the real memory with a minimum of 16 MB and a maximum of 2 GB	Half the available memory with a minimum of 16 MB and a maximum of 512 MB	c

"available memory" is the smallest of real (physical) memory and the RLIMIT_AS value.