Same SID,System No. & same hostname with Different IP

[Former Member]

Hello All,

Can you please let me know the Technical Feasibility of the below scenerio.

Within the same Primary Network, I need to build another SAP System with the same SID, Same System No. in a Server whose hostname will be also same as of a existing SAP System but different IP.

This SAP System needs to be build temporarily for 2 days for Testing purpose.

Please dont ask me the reason for it - please let me know if it is technically feasible.

Here is the scenerio again for more clarity:

Existing SAP System: PRD,00,hostname1(IP:X.X.X.X)

In the same network, another Server(box) is configured with hostname1 - but IP is different - Y.Y.Y.Y

Now in this hostname1(Y.Y.Y.Y) I need to build another SAP System PRD with System No. 00 from the backup of existing System PRD. After build, there will be some testing and System will be dismantled.

Can I build this SAP System PRD,00 in hostname1(Y.Y.Y.Y) ?

Thanks!

[JPReyes · Accepted solution]

Simply for DNS reasons you cannot have 2 servers with the same hostname / fqdn running in the same domain at the same time.

Regards, Juan

[Reagan]

Hello

Same SID,System No. & same hostname with Different IP

To the best of my knowledge you cannot have 2 systems with same host-name.

Secondly if the intention is to create a test system for testing purposes, you should create a test system without having any impact on the production (different SID and machine) and not in a topsy-turvy way.

Cheers

RB

[former_member188073]

Hi,

I remember a trickery i used when i was in college. I download the trial version of VMWare.

And see if you can do what you want to.

Regards,

Varun

[Former Member]

This is what my Network/Unix Team is saying - Externally this new box will appear as hostname2....but internally if we run the command hostname - it will return hostname1...So,

Externally this system is seen as hostname2. But within the system the name will be changed to hostname1 so that there will not be any conflict.

[former_member364620]

I assume they are talking about installing  another SAP instance on the same physical server under different virtual hostname. 

If so, you still can do that but you have to have different system number.

If you don;t change the system number, you will have all kids of issues starting with SAP gateway ending with users logging on to different system.

Strongly advice to change the system number.

Cheers

Matt

[Former Member]

No..its a different physical server hostname2 with alias hostname1 and IP Y.Y.Y.Y

PRD,00,hostname1 is my original/existing SAP System

[former_member364620]

Net effect is the same, SAP uses combination of hostname and system number for internal communication as well as connections to the system. I still recommend you use different system number on hostname2.

You can copy SAP off hostname1 to hostname2 and reconfigure it to use different system number.

[Former Member]

Thanks Matt,

If I shutdown SAP on PRD,00,hostname1(IP:X.X.X.X) (my original/existing SAP System)

for a certain time period.

Can I use SAP on PRD,00,hostname2 (alias hostname1) (IP:Y.Y.Y.Y) during that time period for testing? without any effect on my original/existing SAP System?

After Testing is complete - we will dismantle this System and start SAP on the orginal System.

[former_member364620]

Yes you can. You can run the identical copy as long as the original system is shutdown.

Thanks

Matt

[JPReyes]

I don't understand in what case scenario is acceptable to call downtime on your production system for testing?

You can easily do a Homogeneous System Copy to a Sandbox and run your test there.

Regards

Juan

[Former Member]

Thanks Matt.

I will STOP SAP on PRD,00,hostname1(IP:X.X.X.X) (my original/existing SAP System).

I hope shutting down the server is not essential, is that right?

Thanks,

[former_member364620]

This is correct. Shutting down SAP on the production server will be enough to keep this system safe.

Since you are willing to take a production system outage, consider taking a backup of production and restore it after the test. Not a best practice because it requires your production system to be unavailable.

That makes me think of another potential issue. In either case you have to make sure your test system doesn't communicate to the outside world during the test. For example, it may make RFC calls, send IDOcs, printouts, emails, faxes, alter your tax database etc. with test information that may be taken as valid production data. This should be covered in your planned test.

To the point that many people have raised. This is NOT a best practice. For not much more work you can put up entirely separate SAP instance without impact to your production environment.

Matt

[former_member364620]

You can do this provided that these two systems would not be able to see each other on the network.

This means that a client who can connect to one of them cannot connect to the other.

This is going back to Juan's point. You will get random name resolution and have people connecting to one or the other system without ability to tell or change, which system they're in.

Matt

[divyanshu_srivastava3]

Which host name will you get when you will ping with an ip address ??

Then how will TCP/IP host name resolution protocol work ??