Multiple Oracle databases on Single host

[Former Member]

Hi Gurus,

I am new to SAP World. We are planning to install multiple SAP systems (ECC/BW/SRM/XI) on a single host with Oracle 11.2.0.2. As per SAP instguide, the Oracle RDBMS software should be owned by ora<SID>:dba. So we are planning to install the oracle software for the first dev system ERD under 'oraerd:dba' id. And the next will be under 'orabwd:dba' and the third under 'orasrd:dba'.

My questions is, instead of having multiple ORACLE_HOME's owned by individual id's, can I have one consolidated Oracle_Home owned by 'oracle:dba' which then controls all the oracle db's and its datafiles.

I know there is a SAP Note to do this for Oracle RAC (prd is being planned this way), but can we do the same for Single instance also.

Best Regards

Shiv

[volker_borowski2]

Hi,

Note 105047 - Support for Oracle functions in the SAP environment

53. ORACLE_HOME sharing
Not permitted (that is, each database must have its own set of Oracle executables).
Reason: This avoids dependencies with patches and upgrades.

If you got a support answer contradicting to this note, you better file that one away on read only media,

to make sure you get support in case of trouble.

Volker

[Former Member]

Hi Orkun,

I am sorry, I think you misunderstood me. The prod RAC will have 3 physical nodes, but there will be only one RDBMS software on this cluster (installed on shared/cluster filesystem) which will support multiple Oracle RAC db's.

-Shiv

[Former Member]

Hi Shiv,

I understand the situation, clearly. No problem with it. At this stage, you will not be able to have one Oracle home on a single host, without RAC.

Best regards,

Orkun Gedik

[Former Member]

Hi Orkun,

For Prod installation this is the only way SAP supports. They told us that all the Oracle components(CRS/RDBMS/db files) should be owned by one id, 'oracle', no matter how many SAP instance you install.

The only supported way was to install the individual SAP systems using the normal single instance install (using its own 'ora<sid') and then do a migration to RAC cluster under the ownership of 'oracle'.

That was the reason why we plan to do the same type of consolidation on the dev system, so that we have similar environment.

And for the restrictions, yes, we will have to take downtime (controlled) bringing all db's down for patching/upgrades. But the advantage is that we reduce our physical server footprint by a huge number.

-Shiv

[Former Member]

Hi Orkun,
> For Prod installation this is the only way SAP supports. They told us that all the Oracle components(CRS/RDBMS/db files) should be owned by one id, 'oracle', no matter how many SAP instance you install.
> The only supported way was to install the individual SAP systems using the normal single instance install (using its own 'ora<sid') and then do a migration to RAC cluster under the ownership of 'oracle'.
> 
> That was the reason why we plan to do the same type of consolidation on the dev system, so that we have similar environment. 
> And for the restrictions, yes, we will have to take downtime (controlled) bringing all db's down for patching/upgrades. But the advantage is that we reduce our physical server footprint by a huge number.
> 
> -Shiv

Hi Shiv,

So, you got the answer from SAP support I couldn't understand why they recommended RAC installation on a single host? Is it must or should be?

Best regards,

Orkun Gedik

[Former Member]

Hi Orkun,

Thanks for your reply. Its a must or its just better to have under individual O_H. The reason we were looking to out all under 'oracle' was that our DR site for the prod is going to be single instance physical standby using DG. SAP recommends to have the OS user on the DR host to be oracle, so that there are no issues with permissios for log shipping.

So we will end up having multiple db's system running under 'oracl' on the DR site.

-Shiv

[Former Member]

Hi Orkun,
> Thanks for your reply. Its a must or its just better to have under individual O_H. The reason we were looking to out all under 'oracle' was that our DR site for the prod is going to be single instance physical standby using DG. SAP recommends to have the OS user on the DR host to be oracle, so that there are no issues with permissios for log shipping. 
> So we will end up having multiple db's system running under 'oracl' on the DR site.
> 
> -Shiv

Hi Shiv,

Technically, there's no restriction to configure your system, by this way. But from SAP point of view; at the first step, because the the installation is not completed as referred by SAP installation guide, you will not able to get support by SAP. For the instance, if you face with a problem during the productive, SAP may not support your installation.

Secondly, you may face with the problems at the database upgrades and applying patches. For example, you need to stop all the databases when you decided to patch one of them.

I can count many restrictions about this issue. As a summary, from technical way, it is possible to have one Oracle home, but it is strongly recommended to have different Oracle home folders for each Oracle installation.

Best regards,

Orkun Gedik

[Former Member]

Hi,

RAC is a different issue. It is real application clusters which is cluster solution for Oracla database.

In your case, you should use different Oracle homes.

Best regards,

Orkun Gedik