Hi, I am using tomcat5.0 web server in Linux. At the time of tomcat startup, the maximum heap size for JVM is specified using Xmx parameter in catalina.sh, for e.g.
java -Xms128m -Xmx1337m -classpath jre/lib/tools.jar:tomcat/bin/bootstrap.jar org.apache.catalina.startup.Bootstrap start The issue I found in some linux machines is that if Xmx parameter is too high, The tomcat does not startup and the tomcat log entry is as below " Error occurred during initialization of VM. Could not reserve enough space for object heap." When Xmx parameter value is reduced manually then only tomcat works. For example, in one scenario, the total physical memory of the machine was 4GB, Xmx parameter was 2640MB, but tomcat did not start and I got the message as above. When I reduced the Xmx parameter to 1.5GB, then the tomcat was Started. I am looking for logic to specifying the optimal value for Xmx parameter so that the parameter need not be changed manually. In other words, is there any relationship between optimal Xmx value and some of the rseources in machine like total physical memory, available physical memory, swap space etc. Couple of observations that I had: 1. For 32 bit processors the maximum heap size can be specified is 1.8GB. But tomcat can use both 32 bit processor as well as 64 bit processor 2. When I gradually increase the Xmx parameter and start tomcat, just after the maximum Value of Xmx parameter for which tomcat works, I find a Error message like " Exception in thread "CompilerThread1" java.lang.OutOfMemoryError: requested 1292 36 bytes for Chunk::new. Out of swap space?" So, it seems to me that Java Virtual machine uses swap space as well as available Physical memory for allocating maximum Heap size. So, I am looking for the logic for specifying optimum value for Xmx parameter which I can specify without any manual intervention. Please provide me any help on this. Thanks Monimoy ___________________________________________________________ Yahoo! Answers - Got a question? Someone out there knows the answer. Try it now. http://uk.answers.yahoo.com/ --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]