Re: That will take me a bit.
df -a
This will show what disk devices are mounted on what directories.
We need to figure out where your tablespace data files are, and where your logs are, and if you are archiving, where your archivelog destination is. If you have many logs, you might have them placed on different file systems, which in turn might end up round robining the high IO points.
The key issue is to identify points of contention.
You might might be able to tell by querying some data dictionary tables. I can't give you the commands since I don't even have a login to an active Oracle 9i instance to check.
You DBA should be able to just tell you. You should then validate by looking in the dirs they tell yoy about.
Are you duplexing the logs? Again, a dba question.
I might be able to answer some of the other questions based on the output of the df command.
When I say database edition, I mean are you using the Veritas Oracle Accelerator, which is also known as Veritas Volume Manager Database Edition. Sorry for not being more specific.