This blog contains experience gained over the years of implementing (and de-implementing) large scale IT applications/software.

Tag: Kernel

SAP Kernel to EXT or not to EXT…

Scenario: You’re at the point where you are installing a new system and your choice of Kernel is down to the EXT version or the non-EXT version.  Which version should you use?

The difference between the EXT version of a Kernel and the non-EXT version of a Kernel, is simply down to the version of the compiler and compilation Operating System used by SAP to compile the Kernel binaries.

As an example, the 7.21 kernel could be compiled on Windows 2003 Server, using the Visual Studio 2010 compiler.
The 7.20EXT kernel could be compiled on Windows 2003 Server, using the Visual Studio 2012 compiler.

The difference is all about the compilation environment, and nothing to do with functionality.  Or is it…
If you look at SAP note 1926209 – “Questions on subjects of 7.20/7.21 EXT kernel and C/C++ runtime“, this would seem to be the case.
However, read SAP notes 1756204 – “Activate fast polling”  and 1728283 – “SAP Kernel 721: General Information” , you will see that it seems to suggest that SAP can and will change the functionality between an EXT and non-EXT kernel (7.21 is used as the example here).
So, be wary and always read up about the benefits of each Kernel, whether EXT or not.

HowTo: SAP Kernel Patch History

Scenario: Your SAP system Kernel has been patched.
You would like to see the patch history of the system and you are running on Windows and SQL Server.

You can view the patch history for a DLL or EXEcutable (such as disp+work) by querying a table in the SQL Server database as follows (changing the <SID>):

SQL>  select * from <SID>.MSSDWDLLS
    where DLLNAME='disp+work.EXE'
order by DLLNAME, HOSTNAME, DLLPATH, LASTDATE, LASTTIME;

The results will provide a complete traceable history of the system including the previous identity of the SAP system, the different application instances and any inconsistencies in the DLL versions.

SAP Kernel Patch History SQL Server

SAP Kernel librfcum.so Missing

When trying to start a SAP system I got an error from the sapstart.log indicating that librfcum.so was missing.
This was not in any of the exe directories or in any of the Kernel distribution files.

During an upgrade, a kernel was patched with a unicode kernel when it should have been a non-unicode kernel.
The correct kernel patch was then deployed into the central exe directory, but it looks like sapcpe did not correctly detect and replace the kernel files on the other instances.

The solution to the missing librfcum.so problem, was to completely remove the kernel files in the instance exe directories, then manually run sapcpe (sapcpe pf=<instance pf>) to re-copy the files from the central exe directory.

This fixed the issue.

How to Check If You’re Using the 6.40 Extension Set 2.0 SAP Kernel

With SAP R/3 Enterprise 4.7 came the 6.40 Kernel.
There are two releases of this kernel, 6.40 Extension Set 1.10 and 6.40 Extension Set 2.0.

When you need to patch the Kernel, you need to know which one to download.
You can tell by executing the “disp+work” binary on UNIX or Windows:

$ id
<sid>adm

$ disp+work

--------------------

  disp+work information
  --------------------
  kernel release                640
  kernel make variant           640_EX2        <<< EXT 2.0
  DBMS client library

$ disp+work

--------------------

  disp+work information
  --------------------
  kernel release                640
  kernel make variant           640_REL        <<< Not EXT 2.0
  DBMS client library