OC4J portal was 'none'

Problem:

We have Oracle Application Server 10g,we shut down the application and rebooted the server which
in application run.But then we can't have start opmn.We we run 'opmnctl startall' OC4J portal
was 'none'.It can't have been alive.

Solution:

ulimit -c unlimited

This command change all limits to unlimited.The problem caused by 'open files' parameter:)