hi all,
we will migrate from Informix IDS 7.31 to Oracle 9i in a month with 50 GB data and 40 GB index data from our Informix time,what is more we will change our hp 4 cpu RISC machine with 2 ibm pseries 630,one is app. server with 4 cpu and the other is db server with 2 cpu which will run as a cluster system.
Our storage capasity is 440 GB will run under ibm FastT700 storage server as RAID 0+1 .We use Baan IV ERP with about 200 concurrent users.

we plan to make our data disk layout for Oracle 9i RDMS as follows;

lv01
system 1024 MB
redolog 2048 MB
rollback 1024 MB
temp 2048 MB
Data N/A
Index N/A
Total Allocated: 200 GB

lv02
Oracle_Binary N/A
lv03
Baan_Binary N/A
Total Allocated: 40 GB

OS related binaries will be located at internal disks.

is this layout good for performance considerations?which of them can be increased/decreased to gain most performance?

Thanks in advance.

I would highly recommend that you get a copy of Oracle 101 Performance Tuning by Gaja Vaidyanatha, Kirtikumar Deshpande, and John Kostelac. This book covers I/O tuning which includes a detailed discussion of RAID and disk layout methodologies. This book is a gold mine of easy to understand information about how the Oracle database works, best practices, and how to make it work better for you.

Gilbert Guymer
Database Administrator
Lufkin Industries, Inc.

Another book that may be useful is a fairly recent (2003) IBM Redbook "Database Performance Tuning on AIX" which was published this year and is available for downloading from IBM as adobe pdf.

We have 2 p620 machines and a user count about half yours but we have databases about double your size.

I do not have any specific experience with the IBM FastT700 device but my suggestions are as follows: what needs to happen with the layout of the data base files for any server is to minimise i/o contention. In your case I think, at the very least you need to have separate "disk spindles" for (a) redlogs, (b) data, (c) indexes (d) oracle std table spaces [system, temp, users, rbs]. You will probably have 2 or 3 copies of the oracle control files which can each be placed on separate internal drives with maybe one on the FastT400 device. If you have multiple redo log groups the groups (a|b) need to be on separate drives (can be on low activity internal drives also)

You didn't mention the amount of RAM you will have. This is very important to have as much as you can afford.

Hope these suggestions help

Terry