
The rolling kernel switch (RKS) can only be used if the kernel versions are RKS-compatible. Before a new kernel is imported, you must check that the compatibility levels of the two kernel versions match.
Definition of RKS Compatibility:
An ABAP kernel version A is compatible with an ABAP kernel version B if a system with instances of both versions can be run. The compatibility of two kernel versions includes all forms of communication and information exchange.
To check whether two kernel versions are compatible with each other, you must know the compatibility level of both versions. The compatibility level is increased as soon as an incompatible kernel change is made. In this case RKS cannot be used.
To display the compatibility level of your system:
You can find out the compatibility level of a new kernel version from the info file of package SAPEXE.SAR on SAP Service Marketplace.
If a new RKS-incompatible kernel has to be imported, RKS cannot be used. In this case you need to restart the entire system and accept a temporary system downtime.