#sapadmin:: EHP Technical Checklist & Best Practice, catalyst to a successful Upgrade – Part I
To ensure a successful EHP upgrade, technically (this blog is focus on the technical aspect, which doesn’t cover functional) , it is important and critical to have a proper planning, preparation, understand what’s happening behind for each critical process (especially during DBCLONE, DDIC_UPG, ACT_UPG, SHADOW_IMPORT_INC and TABIM_UPG and etc); which log file, program to investigate in case of error. Sometimes, we are in an awkward situation when there’s no status indication for long running job, no update to the log, and you see no wps, TP, R3trans is running, you start getting worry and unsure is your upgrade hung or still running.
In this blog, I’ve summarized the catalyst to a successful EHP upgrade which comprise of general planning + preparation, critical & long running EHP upgrade processes. MOPZ is not cover here. I’ll focus more on EHPI, nevertheless, it can be used as a reference for SAPup, since most of the steps, processes are identical.
SAPehpi is used when upgrade SAP ERP 6 to EHP*, SAP EHP4 for ERP to EHP5, SAP NW 7 to SAP NW EHP* and SAP EHP1 for NW 7 to SAP EHP2 for NW7.
General Planning + Preparation:
- EHP Installation/ Upgrade Guide ::Download all the related EHP upgrade guide from SMP and read thru every section, ensure you understanding what you are reading.
Mandatory guide – How to install Enhancement Package 4/5 for SAP ERP 6.0 or How to install Enhancement Package 2 for SAP NW 7.0, Installation Guide – SAP EHPI, using SAP Enhancement Package Installer (SAPehpi) 7.00 , Master guide.
* Most of the preparation task which covered in upgrade guide such as ensure no canceled update in SM13, no inbound/ outbound queue in SMQ1/SMQ2, invalidate temp object in SE14, etc are not covered here.
- EHP Upgrade Notes :: SAP Notes highlighted in the installation guide, sub-notes that mentioned in each and every note are important. Go thru every note to identify is this relevant to your application.
Mandatory SAP Notes –
Note 822379 – Known problems with Support Packages in SAP NW 7.0x AS ABAP – Check all notes that are related and relevant to your System.
Note 1302772 – Central Note – SAP Enhancement Package Installer 7.00 – Carefully go thru and implement the recommendation, for example:
———————< D030559 MAY/06/05 >—————————-
Increase Parameter em/initial_size_MB
To avoid a runtime error in the RUN_RSAIMMERGE_UPG phase, increase parameter “em/initial_size_MB = 1024” to “em/initial_size_MB = 4096” in the instance profile of your target system. –> this mean that at least 4096 MB set for em/initial_size_MB.
SAP Notes for product, OS and DB specific mentioned in Central Note are critical. It is important to follow and implement the recommendation to mitigate all possible errors during upgrade.
For example, if your DB platform is Oracle, you need update statistic, increase open_cursors, processes & sessions parameter before upgrade by following Note 1161052 – Add. Info: SAPehpi/SUM for Systems on Oracle
- SAPehpi version :: Always download the latest SAPehpi tool available in SMP. This is critical as the latest SAPehpi will avoid expected & unexpected bugs.
- Use the latest SAP binary:: Ensure MOPZ is generated accordingly and correctly. All download SPs, Kernel and Stack.XML are copied into download directory. Besides Kernel downloaded during MOPZ generation, please check any updated SAP Kernel (SAPEXE, SAPDBEXE and DW package), lib_dbsl, TP, R3trans and R3load (for SAPup) available in SMP. If yes, please download and copy them to the download directory. Errors and bugs can be avoided by using the latest binary.
SAPehpi will extract dw, TP and R3trans to the exe and exenew automatically. At the end of “Configuration” phase:
- Space :: Ensure sufficient space is allocated before start the upgrade. Example of approximate space needed:
EHPI Directory – 30 -> 50GB (depends on how many SPs you downloading & upgrading)
Download Directory – 20 -> 40GB (depends on how many SPs you downloading)
DIR_TRANS – 30 -> 50GB
Database free space – approximate 20 -> 40% of your current Database size. Again, this is highly depends on how many level of Software Component s you are deploying. Large space is needed to build and store shadow repository in your current database. However, there’s < 10% increase of your current DB size after upgrade as the old DDIC, nametab, and etc will be deleted and replaced.
*EHPI will alert if insufficient DB free space at the end of “Check” phase. For Oracle, you need to create tablespace PSAPSR370X manually.
Take my recent upgrade for example:
DB size before upgrade -> 348GB
DB size after shadow repository created (end of “Pre-Processing”) -> 420GB
DB size after upgraded to EHP5 (downtime completed, before SGEN) -> 350GB (sometimes you’ll notice your DB size is slightly smaller or same with size before upgrade due to the DB-Platform specific compression feature, eg: MSSQL 2008)
- SPAM :: Update your SPAM to latest level available in SMP
- Source Kernel :: Update your source kernel to latest level as well. Again, this action can avoid time-consuming error investigation.
To make this useful to every #sapadmin, valuable and kind input is mostly welcome. Let’s make this a brainstorming section 😉
I’ll talk more on the long running upgrade process in Part II, and thing to look into for each critical process, what process is running and what log to check in case of error.