OS Migration AIX to Linux

[Former Member]

Hello Admins,

One of my customer want to migrate his data center, this migration also includes OS migration for SAP servers from AIX to Linux.

Current system : ECC 6.0, AIX 6.1 and Oracle 10.2, also it is Non Unicode system.

Target system : ECC 6.0, Linux (version is not yet decided) and Oracle 11.2 (which we will upgrade before migration on source system) and non unicode system.

Please suggest -

Which will be the best approach to follow for OS migration.?

Can we achieve this migration with lpar movement during data center migration.?

Is it mandatory to have OS/DB Migration certified consultant for such project and if one don't have that what can be the issues.?

I have read SAP note# 82478 - SAP system OS/DB migration, need some more inputs from your experience.

Thanks in advance.

Regards,

Ashish

[Former Member · Accepted solution]

Hello Ashish,

To expand on what Sharib has already mentioned.

1. You will have to perform a heterogeneous migration. AIX is big endian and Linux is little Endien. Filesystems don't come into the equation for your migration.

2. For OS/DB migrations your consultant must be OS/DB certified (TADM70 or later). If you don't use a certified consultant then you risk losing SAP support in the event of issues.

You have decided to upgrade your Oracle version before the migration. You could export from 10.2 DB and import into a 11.2 directly without having to upgrade your source DB. However, if you want to perform "like for like" tests before/after then you could upgrade before starting as you have planned.

You will find additional information at:

SAP OS/DB Migration Check | SAP Support Portal

Kind Regards,

Amerjit

[Former Member · Accepted solution]

Thank you for the valuable information.

Can you please help me understand on below approach,

I will take an oracle backup of current system (on AIX).

Then I will install SAP system on my Linux box where host name, SID, Instance no. everything will be kept same; And I will also make sure that Oracle SAPDATA files size will remain same.

After the installation,I will restore the database backup on newly installed system which is running on Linux.

I would like to know if this approach can work?

Please suggest.

Thanks,

Ashish

[Reagan · Accepted solution]

You cannot do a backup and restore of a database running on AIX to Linux. You need to do a heterogeneous system copy. This has been discussed numerous times before.

[former_member184628 · Accepted solution]

Hi Ashish,

I would suggest you to contact a OS/DB migration consultant so that you dont land yourself in trouble post migration.

Thanks,

Sharib

[Sriram2009 · Accepted solution]

Hi Ashish

I think it's not possible to restore the Oracle DB in Linux (which is already backup on AIX). You have to follow the steps as per SAP Heterogeneous system copy method.

1. From Source system (That on AIX / Oracle 10.2) SAP Standard method System copy Export.

2. On target system (Linux / Oracle 10.2) import the same by SAP standard method

3. Upgrade the Database from 10.2 to 11.2

BR

SS

[Former Member]

Hello All,

Thank you for all the information.

My oracle DBA says, he can move oracle(10g) database from AIX to Linux (RHEL) using some oracle utilities, and I need to take care of migrating SAP application to Linux.

Client's landscape involve multiple JAVA/DotNet based application as well for which database is oracle and DBA will be migrating it with some oracle utility.

I have gone through some oracle blogs and which suggest RMAN utility for cross platform migration of Oracle database.

Is this possible with SAP applications as well.? or standard heterogeneous system copy is the only option.

I am trying to find out how to achieve minimal downtime as client do not want systems to be down more than 6 hours (not practical) and server sizing of PRD is low which can not be increased-

ECC 6(no EHP) on Oracle 10g

8GB RAM

2 Core CPU

DB size : 450 GB

Is there any other way or option using which we can perform migration with minimum downtime.

Any input on this will be of great help.

Thanks,

Ashish

[Former Member]

Hi Ashish,

I think all the post above is already mentioning that you could only do this with os/db migration (heterogeneous system copy).

I'm not saying that it's not possible using RMAN or other Oracle method, but that will only cover the database. Meanwhile, what we are talking about is SAP environment (Oracle Database for SAP and the Application server) so you should do it with SAP method.

To calculate the downtime process, I suggest you try it first in the Sandbox.

Regards,

Dhanar

[Former Member]

Hi Ashish,

You can try Oracle Golden gate Option where you will have less downtime. Oracle Golden Gate might be expensive but overall it will be always good. You can try in Sandpit first then go ahead in your landscape.

Cheers,

Sharma

[Reagan]

A certified consultant is mandatory. You can avoid the Oracle upgrade to 11G on the source system. If the database is quite big then consider splitting the biggest tables to speed up the migration. As the target system will be on Linux and there is no indication as to which distribution you will be using, I suggest you to read the SAP note 171356 - SAP Software on Linux: General information and follow the note for the relevant Linux distribution and set the target server for the migration. You can set up the Oracle parameters as suggested in this SAP note 936441 - Oracle settings for R3load based system copy

[former_member184628]

Hi Ashish,

Use SAP standard tool using export-import methodology to migrate system.

For migration from AIX to linux, you cannot simply use lpar movement as AIX and linux have different file system.

Is it mandatory to have OS/DB Migration certified consultant for such project and if one don't have that what can be the issues.?

As per SAP, OS/DB migration should only be done by certified OS/DB migration consultant.

Thanks,

Sharib