Thursday, June 18, 2015

SAP System Copy Procedures

Background

My company uses SAP AG's Enterprise Resource Planning software. It as a complex system, but being developed by Germans has its advantages, for example the have many documentation in the form of SAP Notes and other stuff. One of the challenging task in using SAP's ERP is system migration and cloning. Two purposes for the migration : first, if you want to move the system to another hardware. The second, if we need a cloned system to do stuffs without compromising your original system. SAP's term for migration activity is 'System Copy'

Where to start

To find out steps needed to be done for system copy, you could read this slideshare-hosted SAP document here (Best Practices : SAP System Landscape Copy). For another definitive starting point, check out SAP's wiki DOC-8324 System Copy and Migration. I noted that SAP has released Software Provisioning Manager from which we could do system copy, my previous system copy experiences has not involved such software. Anyway lets get down to the basics.

Homogenous or Heterogenous ?

SAP differentiates  homogenous and heterogenous system copy. They states that when the OS or Database is the same, the migration can be done using homogenous system copy. When one of the database or operating system is altered, the migration must be done using heterogenous system copy, with several exceptions. For homogenous system copy, we could use either the database-independent copy procedures or the database-dependent copy procedures. Usually the database-independent is the slower procedure between the two. For heterogenous system copy, there is no option, we can only use database-independent procedure.

Documentation and documentation

According to http://scn.sap.com/docs/DOC-48323, first thing that need to be done is to download the latest system copy guide from https://service.sap.com/sltoolset - Software Logistic Toolset 1.0 - Documentation - System Provisioning, which point us to either Netweaver 7.0 System Copy Guide or Netweaver 7.1 System Copy Guide. The old Best Practices document refers to Best Practice update SAP Note 885343. The Newer system Copy Guide refers us to either SAP Note 1768158 for NW 7.0 or SAP Note 1738258 for NW 7.1., SAP Note 885343 SAP System Landscape copy, and SAP Note
82478 – SAP system OS/DB migration. I noted that the System Copy Guide doesn't contain the steps need to be done to ensure archived data can be accessed, for those we need to refer to the SAP Library Administrator's Guide ->Technical Operations for SAP NetWeaver -> General Administration Tasks -> Data Archiving  and blog DOC-7856 SAP Netweaver Application Lifecycle Management. The guide doesn't specifically note general Oracle Tuning documents (it does refer to r3load optimization for Oracle in  SAP Note 936441) but the blog refers to SAP Note 1918774 (Performance issues when running a SAP Installation / System Copy) which really should be called "Oracle Performance issues when running a SAP Installation / System Copy".

Procedures

In general, the process of system copy consists of :
1. exporting source system
2. transfer the exported data ('load') to target server
3. perform SAP installation procedures on the target system
4. perform DB load on the target system

Test run

For production systems migration, it is highly recommend to do a test run, to measure the amount of downtime needed and to ensure potential problems (as SAP declared, customer-specific problems) are detected and noted before we really do the system copy. The test run consists of :
1. export source database
2. move the export data to target system
3. import data in the target system.
This seems simple, but for large production systems is not .. terabytes of data can be challenging to move, export / import are more or so challenging. For the real migration run, the production system downtime is from step 1 to 3. SAP installation could be done before the test run.

Conclusion

The SAP documentation contains many procedures to follow when doing System copy. It is imperative that the procedures are detected and gathered before actually doing the process.

 



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