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BEA JRockit 1.4.2 SDK Command Line Options by Name

BEA JRockit 1.4.2 SDK uses the command line options listed on this page for configuration and tuning.

Option Name | Description | Used In
-classpath -cp | Tells BEA JRockit JVM where to look for classes and resources. | Configuration
-client | Starts BEA JRockit JVM in the client mode. This option is useful when you are using a small heap and are anticipating relatively short runtimes. You should be aware that setting the JVM type (or accepting the default) will also set the garbage collection algorithm that will be used during runtime. -Client will start a single-spaced, concurrent mark, concurrent sweep garbage collector (see Using the BEA JRockit Memory Management System for more information). | Configuration
-D | Tells BEA JRockit JVM to set a Java system property. These can be read by a Java program, using the methods in java.lang.System. | Configuration
-help | Tells BEA JRockit JVM to display a short help message. | Configuration
-jrockit | Starts JRockit in server mode. This option does the same as starting the JVM with the option -server. |
-server | Starts BEA JRockit JVM as a server-side JVM. This value is the default. You should be aware that setting the JVM type (or accepting the default) will also set the garbage collection algorithm that will be used during runtime. -Server will start a single-spaced, parallel mark, parallel sweep collector (see Using the BEA JRockit Memory Management System for more information). | Configuration
-showversion | Tells BEA JRockit JVM to display its product version number and then continue with startup. | Configuration
-verbose -Xverbose | Tells BEA JRockit JVM to display verbose output. | Configuration
-version | Tells BEA JRockit JVM to display its product version number and then exit. | Configuration
-X | Tells BEA JRockit JVM to display a short help message on the extended options. | Configuration
-Xbootclasspath | Sets the search path for bootstrap classes and resources for BEA JRockit to use instead of those supplied with the J2SE SDK. Specify the names of the directories, .zip, and .jar files, separated by ";" (Windows) or ":" (Linux). | Configuration
-Xbootclasspath/a | Sets the search path for bootstrap classes and resources for BEA JRockit to use instead of those supplied with the J2SE SDK and appends the information to the default bootstrap class path. Example: -Xbootclasspath/a:/path/to/classes | Configuration
-Xbootclasspath/p | Sets the search path for bootstrap classes and resources for BEA JRockit to use instead of those supplied with the J2SE SDK and prepends the information to the default bootstrap class path. Example: -Xbootclasspath/p:/path/to/classes | Configuration
-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 Notes: The alloc option is not available on IA64 systems. Default: If the clear type is not set, the default is alloc on IA32 systems and gc on IA64 systems. | Memory Management
-Xgc | Deploys the specified fixed garbage collector. Parameters: singlecon; Single Spaced Concurrent gencon; Generational Concurrent parallel; Parallel Default: The default is parallel when running with the -server option specified (default behavior) and singlecon when running with the -client option specified. (See information about client and server mode specified above) | Memory Management
-Xgcpause | Prints pause times caused by the garbage collector. | Memory Management
-Xgcprio | Sets the unified garbage collector according to the specified priority: Throughput: The time between when an object is no longer referenced and the time that it’s reclaimed and returned as free memory. The higher the memory throughput the shorter is the time between the two events. Pausetime: The length of time that the garbage collector stops all Java threads during a garbage collection. The longer the pause, the more unresponsive your system will be. | Memory Management
-Xgcreport | Causes BEA 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. | Memory Management
-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. | Configuration
-Xmanagement | Enables the management server in the VM, which needs to be started before the Management Console can connect to JRockit JVM. By using the class= and classpath= parameters with -Xmanagement (-Xmanagement:class= , classpath=) you can specify a management class and its classpath. This option loads the class and causes its empty constructor to be called early in JVM startup. From the constructor, a new thread is then started, from which your management client is run. | BEA JRockit Management Console
-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. This value can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g). Default: The default value depends upon the JVM mode: -Server mode: The default value is the lesser of 75% of physical memory or 1536 MB. -Client mode: The default value is the lesser of 75% of physical memory or 64 MB. | Tuning
-Xmx | Sets the maximum size of the heap. Use the following guidelines to determine this value: On IA32 the maximum possible heap size is about 1.8GB (which is the largest contiguous address space the O/S will give a process). For Windows 2000 the largest possible heap is 1.6 GB and for Windows 2003 it is 1.8 GB. The 1.8GB limit does not apply to IA64 machines, because they have a larger address space. Typically, for any platform you don't want to use a larger maximum heap size setting than 75% of the available physical memory. This is because you need to leave some memory space available for internal usage in the JVM. On IA32 machines running Windows 2000, you can use the 3GB mode to increase the memory available to the process. For more information, please refer to the /GB3 parameter documentation, available from the Microsoft Developers Network. This value can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g). Note: If you encounter OutOfMemory errors, you should increase the maximum heap size according to the preceding guidelines. Default: The default value is the lesser of 75% of physical memory or 1536 MB. | Tuning
-Xnativethreads | Enables the Native Threads system. | Configuration
-Xnoclassgc | Disables class garbage collection. | Memory Management
-Xnoopt | Tells BEA JRockit JVM not to optimize code. | Configuration
-Xns | Sets the size of the nursery in generational concurrent garbage collectors. Optimally, you should try to make the nursery as large as possible while still keeping the garbage collection-pause times acceptably low. This is particularly important if you are creating a lot of temporary objects. Notes: To display pause times, include the option -Xgcpause when you start BEA JRockit 1.4.2 JVM. BEA JRockit 1.4.2 JVM has no specific rule regarding the maximum size of a nursery, however it should never exceed the maximum heap size. Default The default value depends upon the JVM mode: -Server mode: the default nursery size is 10 MB per CPU; for example, the default for a ten CPU system would be 100 MB. -Client mode: the default nursery size is 2 MB. | Tuning
-Xss | Sets the thread stack size. This value can be specified in kilobytes (K,k), megabytes (M,m), or gigabytes (G,g). Note: The minimum thread stack size is 16 kilobytes. If -Xss is set below the minimum value, thread stack size will default to the minimum value automatically. | Tuning
-Xverbose | Causes BEA 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 BEA JRockit . | Configuration
-Xverbosetimestamp | force a timestamp to print out with other information generated by -Xverbose by using the command -Xverbosetimestamp. When you use this command, the time and date will precede the verbose information. | Configuration
-Xverify | Tells BEA JRockit JVM to do complete bytecode verification. | Configuration