Java.lang.out of memory exception:Pergem space error

[priscilla kurian]

I am working with tomcat 7.0.25 and ubuntu.while I am trying to start my application pergem space erro occure in log file.How can I remove this pergem space error in ubuntu-tomcat.Where to ser JAVA_OPTS in catalina.sh
or catalina.bat?how can I set JAVA_OPTS.Please help me.It is an urgent one.Thanks in advance.

[Tim Holloway]

The default PermGen space is 128M, and while not many things use PermGen, Tomcat eats a lot of it, so it's common to run out when re-deploying webapps, or deploying apps such as JPA-based apps that also consume PermGen.

You should be able to ease the pain by creating a file named "setenv.sh" (or setenv.bat, for Windows) in the TOMCAT_HOME/bin directory. Put this line into it:

JAVA_OPTS="-Xms256m -Xmx786m -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256m -XX:+CMSIncrementalMode"

You can adjust the Xms and Xmx if you like - I pulled this from a major server which uses more RAM than average.