Please note: This blog was updated 2nd October 2020 with the current information.  All content is believed to be accurate at the time of publishing, but may change without warning.  

The SAP kernel is the core component of any SAP system. It consists of the executable files that run on the server to handle connections to the system and execute the SAP programs. Using the latest stable kernel is vital to ensure your system runs smoothly.

How to check your kernel

Updating your SAP kernel is the responsibility of the basis team, but any user of an SAP system can check the kernel version to ensure they are keeping it up to date. Use the menu ‘System > Status’ to open this dialogue box:

The ‘Kernel release’ shows the release of your kernel and ‘Sup.pkg lvl.’ shows the support package.

Kernel Release Maintenance

It is important to use a kernel that is still under maintenance from SAP. If your kernel is not under maintenance, you will not get important updates or support from SAP. Running an unmaintained kernel may mean you need to do an urgent unplanned kernel update if you require support from SAP for any issue.

The source for SAP maintenance end dates is the Product Availability Matrix (PAM).  The above table is correct at the time of writing based on the information in the PAM.

Choosing a Kernel Release: Downward Compatible Kernels

Your kernel release does not need to match your SAP product release version or NetWeaver release version.

It is important to check your system meets the requirements for the new kernel in the relevant SAP Note:

• SAP Note 1716826 – Usage of the downward compatible kernel 721 (EXT)
• SAP Note 1969546 – Release Roadmap for Kernel 74x and 75x
• SAP Note 2133909 – SAP Kernel 722 (EXT): General Information and Usage
• SAP Note 2556153 – Using Kernel 7.49 instead of Kernel 7.40, 7.41, 7.42, 7.45 or 7.49

Kernal Support Package Levels

To get the value of running a supported kernel release, you must ensure you update regularly to the latest support package of that release.  The fixes included in kernel support packages include important stability and security updates, and often the most severe security vulnerabilities are fixed in new kernels.

Absoft releases a public review of SAP security vulnerabilities each month, as we provide bespoke reviews to each of our managed service customers.  We help customers decide whether to provide an emergency kernel update to address particular security issues, or if they can safely wait until their next scheduled maintenance.

Kernals in SAP S/4HANA

SAP S/4HANA runs on an SAP kernel in exactly the same way as an SAP ERP 6.0 system.  You should update to the latest supported release, then ensure you regularly apply support packages, exactly as in SAP ERP 6.0.

What are EXT kernels?

All SAP kernels are built on a specific version of the operating system and compiler.  When the operating system and compiler for a particular platform reaches the end of support, SAP will make a newer kernel with a newer version of the operating system and compiler called the EXT kernel.

The EXT kernels for a particular release generally have slightly different compatibility, for example SQL Server 2005 is supported on a 722 kernel, but not the 722 EXT kernel. SQL Server 2014 is supported with the 722 EXT kernel, but not 722.

It is recommended to use the newest (ie. EXT) kernel that is supported for your platform, as it is more likely to be created on a supported platform with a supported compiler.  More information on EXT kernels is available in SAP Note 1553300.

How to Upgrade the Kernel

Kernels are upgraded by simply replacing the executable files on the server with the new versions.  The activity is performed by the basis team.  Kernels contain no business logic so there is limited risk, but minimal testing is required to ensure the system runs well afterwards.

For our Managed Service customers we include the latest kernel alongside any support packages we apply, meaning the new kernel is also tested as part of the testing for the support package.