Stripping / how many disk ?

We want to do RAID 0+1 on a database. But we are not sure about the configuration to use :

-> IBM AIX 4.3.3
-> Oracle 8.1.7
-> application Siebel 7
-> 22 disks

We have the following type of data :
-> rbs
-> temp
-> tables
-> index
-> tables for interface
-> index for interface

The end user query the tables except the interface tables The interfaces table (used by the EIM) are heavily use by the batches. They contains the data which will be integrated into the tables acceded by the end user.

There are heavy batches during the night and less important during the day. But the night batches can overlap the work hours.

I see the following possibilities :

1)
- all the disks into one volume group stripped and mirrored. inconvenient : the endusers will be impacted by the batches.

2)
- one stripped vg (6 * 2) for the tables and index acceded by the end users.
- one stripped vg (3 * 2) for the interface tables and index acceded by the batches
- temp tablespace in a mirrored vg
- rbs tablespace in a mirrored vg

3)
small stripped vg (with 2*2 disks) with a uniform repartition of the activity by mutiple tablespaces.

Personnaly, I think the second possibility is the best. But an another dba is for the third possibility.

What do you think ?

In addition, I should say that it will be applied directly on a production database which is considered as critical. Actually, the users complain about very bad performance.

I know it will not resolve all the problems but the database is actually I/O bound.

Thanks in advance for your opinion and sorry for my english ...

-- 
Bruno Jargot