shadow system during system upgrade

[Former Member]

Hi All,

I am new to upgrade.I would like to know about Shadow System, how it will be created, what happens during the switch between the shadow and original system.

I had read the following blog which helped me to get clarity in the introduction part.

Appreciate if anyone can explain and share some document on this.

Cheers,

Febin Roy

[Former Member · Accepted solution]

Hi Febin,

If you are working on SAP upgrade project you will come across to this term – shadow system or instance and system switch.The background upgrades process. Basically by upgrade we want to get the newest functions that provider offers in its software product that we are currently using. For sure we want to get this done without an interruption to existing, running system. In reality there is always some interruption. We are just trying to minimize it as much as possible. So does the SAP. The background of shadow system is to minimize system downtime during the upgrade.

Shadow system is basically copy of system that is going to be upgraded. This copies system is a bit limited to original one. It has only technical repository (SAP Basis objects) of objects and you cannot run your business processes on it.  More over technical repository is upgraded into version of final release of to be upgraded system. Technically speaking it is used for modification adjustments (famous transactions SPAU and SPDD) and activation of objects. All the support packages and add-ons are imported into this instance as well. By them you get you system to the higher release. Let me mention also that shadow system run in the same database as its original system. They are running in parallel.

During preparation of shadow instance you are still running your original SAP system where all the business processes are being executed normally. At the moment when shadow instance is prepared we do its switch from shadow to original system. This is called system switch when you kind of “exchange” original system with shadow one. By that time shadow system becomes upgraded system.

Regards,

Deva

[Former Member]

Hello Febin,

The creation of Shadow System largely depends upon the type/strategy of upgrade you are going to perform.

If it is a support pack upgrade only, and there is no dependency of downtime I would recommend to follow the strategy of resource minimized - single instance upgrade.

This will ensure a faster upgrade (with longer downtime) and you can skip the Shadow System Creation too.

In case you are going for a complex upgrade like release upgrades with downtime constraints Shadow System proves to be of great asset, I believe enough has been explained in the posts.

So Ill keep it concise. Let me know in case you require more information about it.

Thanks & Regards

Rishabh Goel

[Former Member]

Hi Reagan,

For Ehp4 there is no Installation export, only ECC6 installation export and separate EHP4 file are available as per the below image. Please let me know through which media file i will be able to install ECC6.0 EHP4.

Regards,

FR

[Reagan]

For AS installation you do not need the export DVD's. Download the correct SWPM tool and start the additional AS installation. Sapinst will just create the directories and profiles for the new AS.

RB

[Former Member]

Hai Reagan,

can you please tell me the difference between the application and repository data.

we have a requirement to install a App server (ECC6 Ehp4) when i opened the guide i can see that we need to install ECC6 and upgrade it to EHP4 with SUM tool. so how do i do only for a application server with SUM tool.

can you please share any upgrade document through SUM Tool.

Thanks in advance,

Febin Roy.

[Reagan]

If your requirement is to create a new application server then you don't use SUM, instead you need to use the SWPM (sapinst).

SUM tool is to upgrade / update an existing instance.

Regards

RB

[Former Member]

Hi Deva & RB,

Thanks for the quick response.

I understood the functionality shadow instance now but still i would like to get the clarity on the below questions.

how does the productive data in the original system comes to the shadow system during the switch ?

Does we require downtime during the creation of shadow system?

what are the action required from our end wrt to shadow system creation?

what are the filesystem it uses?

how to check the status of shadow system (eg:dpmon)?

thanks in advance.

Febin

[Reagan]

Hello Febin

If you are talking about the application data then the upgrade tool does not touch them. It works with the repository data.

Shadow system creation is an online phase and no downtime is required.

You just need to make sure that there is enough space on the system for the database to grow. Read the upgrade guide for more information. The file system used for the SUM tool is where the shadow instance kernel and profiles are stored.

You can connect to the shadow SAP system using SAP GUI. The shadow system will have a different system number.

Regards

RB

[Reagan]

I suggest you to read these threads first.

if you are doing an EHP update (Eg: ERP 6.0 EHP5 to ERP 6.0 EHP7 ) then the shadow system is created with the help of the DBCLONE jobs. If you are doing a release upgrade then the shadow is created with the help of the export DVD's.

Regards

RB