JVM memory initializazion error after windows update

I have three Windows Server 2003 with 2 GB RAM.

• Server1 tomcat 5.5.25 jvm version SUN 1.6.0_11-b03
• Server2 tomcat 5.5.25 jvm version SUN 1.6.0_14-b08
• Server3 tomcat 6.0.18 jvm version SUN 1.6.0_14-b08

For the three servers JVM parameters are:

 -XX:MaxPermSize=256开发者_如何学JAVAm
 -Dcatalina.base=C:\Apache Group\apache-tomcat-5.5.25
 -Dcatalina.home=C:\Apache Group\apache-tomcat-5.5.25
 -Djava.endorsed.dirs=C:\Apache Group\apache-tomcat-5.5.25\common\endorsed
 -Djava.io.tmpdir=C:\Apache Group\apache-tomcat-5.5.25\temp vfprintf
 -Xms512m
 -Xmx1024m

For some months everithing worked fine. Last friday we installed some windows updates. After the reboot tomcat doesn't start anymore, with error:

   Error occurred during initialization of VM
   Could not reserve enough space for object heap

We reduced the parameter -Xmx1024m to -Xmx768m and now tomcat starts. But we need greater max heap size What happened to our servers ? Thanks in advance.

Similar issue here http://www.velocityreviews.com/forums/t364972-vm-heap-reservation.html you might want to check for the effect of the specific patches installed in the update

Finally found it!!! The update KB956572 makes Tomcat crash if you specify more than 768M heap size in JVM aprameters. It's a killer update for Tomcat based web servers!