A question about MCOD

[Former Member]

Hello,

Due to some reasons,Our company is going to implement the test and dev system of SCM 5.0 on one Server.During I read the installation document,a question really confused me.What's different between installation of an SAP system in a new database and installation of an additional SAP system in an existing database.Which one we should choose.

And where can i find the more detailed document about MCOD.Especially the steps of operation.

By the way,if I adopt method of MCOD to install two central instance on one server,there have any specially parameter with oracle installing different from normal installation?

Thanks in advance.

[former_member204746]

I'm with KBas, avoid MCOD.

instead, install your DB twice and use them independently. much easier and less risky.

[Former Member]

Thanks for you providing those valuable informations.

The firest instance of SCM has been finishied.The following step should be other instance of SCM for test.But I wanna know which parameter should be different from the first instance.

thanks.

[former_member204746]

mainly the system number and SID.

[Former Member]

Hi Rong,

Our company was using MCOD before but we regret it. We have just moved back to the standard installation. There are a lot of negatives about MCOD. Namely,

1. DB Patching - If something goes wrong, both your DEV and TEST will be effected at the same time.

2. Downtime & DB crash - If there are DB related changes, both DEV and TEST needs to be down at the same time.

3. Backup/Restore - backup will be fast but if your restore, then both DEV and TEST will be restored.

4. System refresh - You could not do a refresh from PROD to TEST using DB backup because it will distroy your DEV.

there are more that I can think of but I think you already get the idea.

MCOD is only good if you combine a SAP Instance with other application (like SolMan or IDES or combine SAP DEV and BW DEV, SAP TEST and BW TEST) BUT not DEV and TEST.

cheers,

kbas

[Former Member]

Hi,

Thanks for your reply.

We have no other server resource.We have idea about this.So just tell me how to use Mcod way to implment ,thanks.

[Former Member]

My experience in MCOD is in HP-UX:

Basically, its the same as installing the first instance. Install the central instace as if you are installing a new SAP system.

The trick is in the installation of the DB instance. SAPINST will ask you if you want to install a new DB or install in an existing DB. Select existing DB.

You must use the same DBSID as the first instance but you must specify a new schema id. That will be the schema of the new instance that you want to install. You can download the installation guide from service.sap.com/instguides.

For the file system, the datafiles are stored in the same directory of the first instance. make sure to increas file system size of the existing /oracle/<DBSID>/sapdataX directory to accomodate the new datafiles.

After installation, update the listener.ora and tnsnames.ora. (note 98252)

There is no need to shutdown the existing instance when you install the second instance until you update the listener.ora and tnsnames.ora

Once installed, you now have 2 SAP Central Instance and 1 DB instance (which contains 2 schemas of the 1st and 2nd SAP systems)

To shutdown, you shutdown the first central instance first

login as <sid#1>adm

stopsap r3

exit

then shutdown the second central instance and the database

login sa <sid#2>adm

stopsap (you can also shutdown the database separately if you want)

If you have a powerful server, other option is to install a 2nd separate instance (Central Instance & DB Instance) on the same server. With this, you are not affected with the MCOD problems.

Hope this helps,

kbas