HACMP QUESTION.

[alembertmauricio_cardozom]

Hello SDN Experts.

Our current Production Environment is running in Distributed Installation on

IBM System P5 570 Servers AIX ver 5.2, each node is running two Applications: SAP ERP 2005 SR1 (ABAP + JAVA) and CSS. (Customer Service System)

Node One

u2022 SAP Application (Central Instance, Central Services)

u2022 Oracle 9i Instance for CSS Application.

Node Two.

u2022 Oracle 10G Instance for SAP Application

u2022 CSS Application.

To improve performance we are planning to create a new LPAR for SAP.

According to the IBM HW Partner LPAR is logically isolated with different HW/SW resource(CPU/Memory /Disk resource, IP/hostname/mount point)...

Additionally we are planning to implement HACMP ver 5.2 on both nodes, we do not want to use ORACLE RAC 10G because it will implies to buy a new ORACLE RAC license. I have the following questions:

Questions:

1) Is it true that once a system is already installed and running in production that it is very difficult to implement HACMP?

2)Can we use JFS (journaled file systems) with HACMP for SAP ERP 2005 and Oracle 10 G ? according to SAP ERP 2005 SR1 ABAP + Java on AIX : Oracle Page 28.

3) Must we need to use GPFS ver 2.3 + HACMP 5L according

SAP Note: 527843 - Oracle RAC support in the SAP environment.

We want to use HACMP 5L instead of ORACLE RAC 10.2.

Thanks for your comments.

AMCM.

[stefan_koehler]

Hello,

> 1) Is it true that once a system is already installed and running in production that it is very difficult to implement HACMP?

Normally it isn't difficult, but you need to think about some things (IP address / hostname takeover, shareable directories - maybe via NFS and so on...). The other thing is how many nodes are included in the HACMP environment.

We are clustering our DB server (of course) and one "big" rfc application server with HACMP. All sap relevant directories are shared via NFS (except the database directories).

> 2)Can we use JFS (journaled file systems) with HACMP for SAP ERP 2005 and Oracle 10 G ? according to SAP ERP 2005 SR1 ABAP + Java on AIX : Oracle Page 28.

Yes you can - but if you are using JFS you have some i/o restrictions. For the restrictions and comments take a look at sapnote #999524

> 3) Must we need to use GPFS ver 2.3 + HACMP 5L according

> SAP Note: 527843 - Oracle RAC support in the SAP environment.

Why using Oracle RAC and HACMP?

- RAC: "Fail-over" and load distribution

- HACMP: Fail-over

Regards

Stefan

[markus_doehr2]

Maybe I wasn´t clear - I will try again

HACMP has the option of implementing scalable services - means, you can at a certain load of the system startup another instance of a specific service (e. g. an additional SAP application server).

A database server is by default "single instanced" - means, if you want to make it scalable, you must make the software aware of it - and that is done by implementing RAC.

When a RAC instance is running, there are two instances (be it physical or LPARs) working on the same files in the same filesystem. To make this happen you need to implement the database on a cluster filesystem, which is in AIX case GPFS.

You can´t implement HACMP as scalable service for Oracle without implementing RAC.

Markus

[markus_doehr2]

> According to the IBM HW Partner LPAR is logically isolated with different HW/SW resource(CPU/Memory /Disk resource, IP/hostname/mount point)...

yes, see

http://www.redbooks.ibm.com/abstracts/sg246251.html

> 1) Is it true that once a system is already installed and running in production that it is very difficult to implement HACMP?

What do you mean with "difficult"? Can you elaborate?

> 2)Can we use JFS (journaled file systems) with HACMP for SAP ERP 2005 and Oracle 10 G ? according to SAP ERP 2005 SR1 ABAP + Java on AIX : Oracle Page 28.

> 3) Must we need to use GPFS ver 2.3 + HACMP 5L according

> SAP Note: 527843 - Oracle RAC support in the SAP environment.

>

> We want to use HACMP 5L instead of ORACLE RAC 10.2.

HACMP is used to make applications highly available. The question is what you actually want to do. You wanna implement RAC (to share the load across multiple database servers) or do you want to make the system highly available?

Markus