I see this thread was from a long time ago. But i found that thread when i was searching for something else, and as i knew a solution and I don't want to loose the habit to contributte, here we go :)
Ashwin you had just a simple problem of permission denied.
To solve it you need set write permission to openacs user on aolserver directory
# avoid pid not found errors in the log
mkdir /usr/lib/aolserver4/log chown root:web /usr/lib/aolserver4/log chmod 775 /usr/lib/aolserver4/log
this is already on our docs:
