The long term persistence mechanism for the application server will still be to a database.
The in memory instances of the data will just be recently used entities in a cache.
The pasivation of beans has nothing to do with the long term storage of your data.
Have a look at http://www.theserverside.com/books/wiley/masteringEJB/index.tss
cache size is 1000
pool size is 1000
how about if I created 5000 eneity beans.
the cache & pool will be both full. Where are the remaining 3000 active beans? Are they so-called long term persisted?
Are you really looking at adding 5000 entities in a single transaction?
Sometimes it's really needed. Imagine import operation with some bussiness logic, where atomicity of a whole import is needed.
Please take a look at my case http://www.jboss.org/index.html?module=bb&op=viewtopic&t=47221. I still don't know if there's a bug (some kind of memory leak in JBoss) or if I do sth wrong.