tomcat6.0.28 内存溢出PermGen Space

我在tomcat 6.0.28 的servlet.xml设置了虚拟主机分了三个站点，

.................

<Host name="www.ruijicn.com" appBase="aaaapps"
unpackWARs="true" autoDeploy="true"
xmlValidation="false" xmlNamespaceAware="false">
<Context path="/china" docBase="f:apache-tomcat-6.0.28aaaapps" debug="0" reloadable="true" crossContext="true"/>
</Host>

<Host name="bbs.ruijicn.com" appBase="bbsapps"
unpackWARs="true" autoDeploy="true"
xmlValidation="false" xmlNamespaceAware="false">
<Context path="/bbschina" docBase="f:apache-tomcat-6.0.28bbsapps" debug="0" reloadable="true" crossContext="true"/>
</Host>

...............

正常运行了一天多时间就报错

报Java head Space错误的，后我对bin目录下的catalina.bat 做了修改如下

rem ----- Execute The Requested Command ---------------------------------------
set JAVA_OPTS=-Xms128m -Xmx512m （这就是增加的地方，其他都没有变）
echo Using CATALINA_BASE: "%CATALINA_BASE%"
echo Using CATALINA_HOME: "%CATALINA_HOME%"
echo Using CATALINA_TMPDIR: "%CATALINA_TMPDIR%"
if ""%1"" == ""debug"" goto use_jdk
echo Using JRE_HOME: "%JRE_HOME%"
goto java_dir_displayed
:use_jdk
echo Using JAVA_HOME: "%JAVA_HOME%"
:java_dir_displayed
echo Using CLASSPATH: "%CLASSPATH%"

........

重启后又运行了一天，后开始报错 PermGen Space

日记如下：[org.springframework.web.struts.ContextLoaderPlugIn] - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name \'mySessionFactory\' defined in ServletContext resource [/WEB-INF/classes/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.OutOfMemoryError: PermGen space
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1337)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
at java.security.AccessController.doPrivileged(Native Method)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:423)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:729)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:381)
at org.springframework.web.struts.ContextLoaderPlugIn.createWebApplicationContext(ContextLoaderPlugIn.java:354)
at org.springframework.web.struts.ContextLoaderPlugIn.initWebApplicationContext(ContextLoaderPlugIn.java:295)
at org.springframework.web.struts.ContextLoaderPlugIn.init(ContextLoaderPlugIn.java:225)
at org.apache.struts.action.ActionServlet.initModulePlugIns(ActionServlet.java:869)
at org.apache.struts.action.ActionServlet.init(ActionServlet.java:336)
at javax.servlet.GenericServlet.init(GenericServlet.java:212)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1172)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:992)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4058)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4371)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1116)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1214)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:293)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1337)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1601)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1610)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1590)
at java.lang.Thread.run(Thread.java:619)

忙活了一天，还是不知道怎么解决这个问题，还请大家多多指教！