Command Line Options by Name

-classpath
-cp

Tells WebLogic JRockit JVM where to look for classes and resources.

-D

Tells WebLogic JRockit JVM to set a Java system property. These can be read by a Java program, using the methods in java.lang.System.

-help

Tells WebLogic JRockit JVM to display a short help message.

-showversion

Tells WebLogic JRockit JVM to display its product version number and then continue with startup.

-verbose
-Xverbose

Tells WebLogic JRockit JVM to display verbose output.

-version

Tells WebLogic JRockit JVM to display its product version number and then exit.

-X

Tells WebLogic JRockit JVM to display a short help message on the extended options.

-Xallotype

-Xallocationtype

Sets the type of allocation.

Parameters:

• global; global allocation

• local; thread local allocation

For details on these options, please refer to Table 2-2 in Tuning the WebLogic JRockit JVM.

-Xbootclasspath

Sets the search path for bootstrap classes and resources. Specify the names of the directories, .zip, and .jar files, separated by ";" (Windows) or ":" (Linux).

-Xcleartype

Defines when the memory space occupied by an object that has been garbage collected will be cleared. The parameters listed below determine when the space is cleared.

Parameters:

• gc; cleared during garbage collection

• local; cleared when a thread-local area is allocated

• alloc; cleared when that space is allocated for a new object

For details on these options, please refer to Table 2-1 in Tuning the WebLogic JRockit JVM.

Notes:

• The -Xcleartype:local option is available only if the -Xallocationtype is set to local.

• The alloc option is not available on IA64 systems.

-Xgc

Deploys the specified garbage collector.

Parameters:

• gencopy; Generational Copying

• singlecon; Single Spaced Concurrent

• gencon; Generational Concurrent

• parallel; Parallel

The default is gencopy if -Xmx is less than 128MB; otherwise, it's gencon.

-Xgcpause

Prints pause times caused by the garbage collector.

-Xgcreport

Causes WebLogic JRockit JVM to print a comprehensive garbage collection report at program completion. The option -Xgcpause causes the VM to print a line each time Java threads are stopped for garbage collection.

-Xjvmpi

Enables and disables groups of JVMPI events when running JVMPI. The events are:

• entryexit (default is ON)

• allocs (default ON)

• monitors (default (ON)

• arenasdelete (default OFF)

Note: JVMPI is an experimental feature in the Java 2 SDK and is not yet a standard profiling interface.

-Xmanagement

Enables the management server in the VM, which needs to be started before the Management Console can connect to WebLogic JRockit JVM.

-Xms

Sets the initial size of the heap. You should set the initial heap size (-Xms) to the same size as the maximum heap size.

The default is 16 MB if maximum heap size is limited to less than 128 MB, otherwise 25% of available physical memory, but not exceeding 64 MB.

This value can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g).

-Xmx

Sets the maximum size of the heap. You should set this value as high as possible, but not so high that it causes page-faults for the application or for some other application on the same computer.

The default is the lesser of 75% of physical memory and 400 MB when running gencopy; when running another garbage collector, the default is the lesser of 75% of physical memory and 1536 MB.

This value can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g).

-Xnativethreads

Enables the Native Threads system. This option is the default, therefore you only need to specify it when you want to change the method from thin threads.

-Xnoclassgc

Disables class garbage collection.

-Xnohup

When specified, tells WebLogic JRockit JVM not to watch for or process CTRL_LOGOFF_EVENT or SIGHUP events.

-Xnoopt

Tells WebLogic JRockit JVM not to optimize code.

-Xns

Sets the size of the young generation (nursery) in generational concurrent and generational copying garbage collectors (these are the only collectors that use nurseries). If you are creating a lot of temporary objects you should have a large nursery.

The default is default is 10 MB per CPU with a gencon garbage collector and 320 KB per CPU with gencopy.

This value can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g).

-Xss

Sets the thread stack size; can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g).

-Xthinthreads

Implements the WebLogic JRockit High Performance Threading System (Thin Threads). This option is not available on IA64.

Warning: Thin threads is experimental functionality in this version of WebLogic JRockit, and is not recommended for general use. This feature is subject to change without notice.

-Xverbose

Causes WebLogic JRockit to print to the screen, upon startup, specific information about the system. The information displayed depends upon the parameter specified with the one of these options:

• codegen
• cpuinfo
• gc
• load
• memory
• Opt

For a description of these options, please refer to Table 3-1 in Starting and Configuring WebLogic JRockit.

-Xverify

Tells WebLogic JRockit JVM to do complete bytecode verification.