Is there any relationship between heap and perm size for JBoss? I'd like to increase max heap size but I'm not sure what sort of impact it will have for perm size. I'm running JDK 6. Currently I don't run into perm gen issues, but if I increase heap size is there an implicit relationship that requires me to increase perm gen space? Is there any rule of thumb essentially is what I'm asking?
No, you do not necessarily need to increase perm gen size, if you increase the overall heap size. The perm gen space holds the classes loaded by the JVM. If your deployed application does not change, the amount of data to store in the perm gen space also stays the same - even if the overall available heap space is increased.
The relation ship is rather the other way round - if you increase the perm gen size, you will have less heap space available for your application -> in this case, you would probably consider to also increase the overall heap size.