二、命令列表

jvm_3">2.1 jvm相关命令

vmoption_JVMoption_4">2.1.6 vmoption（查看和修改 JVM里诊断相关的option）

参数说明：

命令	说明
vmoption	查看所有的选项
vmoption MinHeapFreeRatio	查看指定的选项
moption MinHeapFreeRatio 50	更新指定的选项

vmoption__14">举例1：vmoption 查看所有的选项

基础语法：
vmoption

[arthas@18139]$ vmoptionKEY                                                       VALUE                                                     ORIGIN                                                    WRITEABLE                                                
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------HeapDumpBeforeFullGC                                      false                                                     DEFAULT                                                   true                                                     HeapDumpAfterFullGC                                       false                                                     DEFAULT                                                   true                                                     HeapDumpOnOutOfMemoryError                                false                                                     DEFAULT                                                   true                                                     HeapDumpPath                                                                                                        DEFAULT                                                   true                                                     CMSAbortablePrecleanWaitMillis                            100                                                       DEFAULT                                                   true                                                     CMSWaitDuration                                           2000                                                      DEFAULT                                                   true                                                     CMSTriggerInterval                                        -1                                                        DEFAULT                                                   true                                                     PrintGC                                                   true                                                      DEFAULT                                                   true                                                     PrintGCDetails                                            true                                                      VM_CREATION                                               true                                                     PrintGCDateStamps                                         true                                                      VM_CREATION                                               true                                                     PrintGCTimeStamps                                         false                                                     DEFAULT                                                   true                                                     PrintGCID                                                 false                                                     DEFAULT                                                   true                                                     PrintClassHistogramBeforeFullGC                           false                                                     DEFAULT                                                   true                                                     PrintClassHistogramAfterFullGC                            false                                                     DEFAULT                                                   true                                                     PrintClassHistogram                                       false                                                     DEFAULT                                                   true                                                     MinHeapFreeRatio                                          40                                                        DEFAULT                                                   true                                                     MaxHeapFreeRatio                                          70                                                        DEFAULT                                                   true                                                     PrintConcurrentLocks                                      false                                                     DEFAULT                                                   true                                                     UseAppCDS                                                 false                                                     DEFAULT                                                   true                                                     FlightRecorder                                            true                                                      MANAGEMENT                                                true                                                     StartFlightRecording                                                                                                DEFAULT                                                   true                                                     MemoryRestriction                                         none                                                      DEFAULT                                                   true                                                     ResourceManagement                                        false                                                     DEFAULT                                                   true                                                     ResourceManagementSampleInterval                          -1                                                        DEFAULT                                                   true                                                     
[arthas@18139]$

vmoption_MinHeapFreeRatio__49">举例2：vmoption MinHeapFreeRatio 查看指定的选项

基础语法：
vmoption MinHeapFreeRatio

[arthas@18139]$ vmoption MinHeapFreeRatioKEY                                                       VALUE                                                     ORIGIN                                                    WRITEABLE                                                
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------MinHeapFreeRatio                                          40                                                        DEFAULT                                                   true                                                     
[arthas@18139]$