OS/DB Migration
Naveen kumar.H
You have a SAP NW04 system running in your landscape with SP19, and suddenly there is a request from your manager that you need to set up one more system with the same Release and SP, as you need it for some training purpose within 2 hrs. You are perplexed!! You know that installing the systems and patching it would take at least 4-5 hrs depending your hardware, what else can you do?
SAP has an answer for these kind of situation, to be specific its more than the above scenario.SYSTEM COPY or OS/DB migration is the solution for these kind of situations, not only these , may be you have to install it on other OS/DB combinations, you can just do it within 1-2 hrs. Lets us discover what the various options that are provided by SAP to make this Migration.
To begin with, lets us be clear with some of the terminologies of system Copy.
Source system
The SAP system containing the original database is called as source system.
Target system
The system to which the database is to be imported is called as Target system
Homogeneous system copy
During the system copy if you use the same operating system and database platform in source as well as target system is called Homogeneous system copy.
Heterogeneous system copy
During the system copy if you change either the database or the operating system or both of them in the target system as compared to source,such kind of system copy is called Heterogeneous system copy.
Export CD
When you perform a system copy on Source system, you will be prompted to give the location of the folder where the SAPINST is going to dump the database and the SDMkit.jar file. You manually create this empty folder and after successful system copy you find the database and SDM archived in this folder.You have to manually copy this folder ( now referred as Export CD to the desired location ) and then start installing on to the target system. The SAPINST would prompt you to enter the location of the export CD, and you would provide the necessary path where you have dumped this CD.
NOTE : SAP strongly recommends that you only perform OS /DB migration only when you have a strong knowledge about OS/DB and other aspects. Perform heterogeneous system copy only if you are a certified SAP consultant.
You can find all the related documents on OS/DB migration in the following location
http://service.sap.com/systemcopy
First of all let me start of with NW04 OS/DB migration. I will be concentrating more on AS-JAVA OS/DB migration.
SAP provides 2 different procedures of system copy.
Data base specific system copy
This procedure can be used in both homogeneous and heterogeneous system copy scenarios. What does this exactly mean is that you have to separately backup the Database , and then the SAPINST will only archive the Sdmkit.jar only. You have to manually restore the database on the target system and the SAPINST will only restore the SDM. To elucidate,
Let us assume that you have to perform a system copy on system that is running on WINDOWS and SAPDB. First of all using SAPDB manager you take the database backup of the instance and then run the SAPINST. SAPINST is only going to archive the SDM.
Now if the target system also WINDOWS and SAPDB then you can restore the Database and the SAPINST would restore the SDM. But if the target system is of the combination WINDOWS and SQL, I am afraid that the Database cannot be restored. So the possible solution is Data base Independent system copy.
Data base independent system copy
This procedure is used only in heterogeneous system copy scenarios. From the above scenario it is clear that, if the database is changed and if you had performed Data base specific system copy you cannot restore the database. Hence SAP suggests that use this procedure where, the database is archived immaterial to the type of the database.
If you have your Source system on WINDOWS ,SAPDB and you choose this Data base independent system copy, you need not perform Backup , instead SAPINST using the methods of Jload and R3 load would archive the database and also the SDM and hence even though your target systems is WINDOWS-ORACLE or LINUX-ORACLE , no matter what you can perform your OS/DB migration.
Before you start executing the OS / DB migration, Check the compatibility of the source and the target system, You can find the Matrix in the link below
http://help.sap.com/saphelp_erp2005vp/helpdata/en/21/692225b246b24f9202cb4433b5d691/frameset.htm
There is a Slight difference in executing NW04 system copy and NW04s system copy. You can only execute NW04 system copy by executing the SAPINST with an additional parameter. i.e.
./sapinst product_cp.catalog
Kindly refer to the system copy guide for more information.
SAP insists you to use the Patch DVD’s fo NW04 system copy rather than normal SP9 DVD”s.
When you are performing a Heterogeneous system copy, you would be prompted to enter the Migration key. In order to get the key, kindly raise a customer message under BC-INS and provide the details of Source system like OS / DB and also the details of the target system and also the SOURCE.PROPERTIES file that is created when you create an export CD.
When you want to perform a NW04s system copy, you just have to execute the SAPINST, preferably choose the latest SR2 DVD’s.
Now let me discuss some of the known bugs during system copy and the related CSN and Notes for the same.
To start with, Before performing NW04 system copy there is a note that mentions about the pre-requisites for it. Kindly refer to Note 785848 and 711093. You can avoid many errors by referring to these notes. Believe me!!!
One common error while executing the NW04 system copy on AS-JAVA + AS-EP using NW04 SP9 DVD’s is “Portal version not found”. This is because the SAPINST is looking for the version in some folder structure where the version.txt is not at all available. So you have to manually copy it from different folder to the desired one. Kindly refer to the Note 847491.
During NW04 homogeneous system copy using SP9 DVD’s the SAPINST will prompt the migration key!! This is also a bug as the migration key is only needed in case of heterogeneous system copy. Hence SAP insists to use PATCH DVD’s where they have fixed most of the bugs.
If you are executing the NW04 system copy of portal components using SP9 DVD’s, you would encounter some errors while installing it on target system. The common error would during SDM installation step, The sapinst would error out at this step. Kindly refer to the Note 755132.
After successful Installation on target system, the visual administrator does not come up. Refer to the Note 937708.
This one is one of the most interesting, The Java bug, After successful installation on target system, the server0 node does not come up. The node keeps fluctuating between starting and starting framework. You feel frustrated, Don’t worry refer to this CSN message 1458040 2005, or you can refer to the link Sun’s bug .
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=2121269
So these are the common bugs and fixes that were encountered, Hope this blog would solve most of your problems during OS/DB migration.
Naveen kumar.H is a budding Netweaver XI Technology consultant
