Post on 13-Apr-2017
SAP Rolling Kernel Switch
• The Rolling Kernel Switch (RKS) can be used to minimize the planned down;me in high availability systems in order to implement a new kernel patch level
• This document focuses on the manual RKS available for 72x releases of SAP NetWeaver
• The document is aimed at system administrators responsible for upgrading the kernel of SAP NetWeaver systems opera;ng the 721 kernel
Introduc5on
• Applica;on severs of the system being patched must operate temporarily with a different kernel version
• The kernel versions in ques;on must be compa;ble – i.e. the old kernel must be able to operate alongside the new kernel in the same SAP system
• The system is a high availability system with clustered central services (SCS) and associated replicated enqueue managed by an enqueue replica;on server (ERS)
Pre-‐Requisites
Prepara5ons • Download and extract the new kernel to your soPware
repository
• Prepare the SCS for RKS – copy the extracted “StoC.xml” file to the directory of the SCS instance denoted by system parameter $DIR_HOME
• Use “sapcontrol -‐nr 00 -‐func;on ParameterValue DIR_HOME | tail -‐1” to determine this loca;on if you’re not sure
• Physically switch in the new kernel by copying the newly prepared kernel into the /sapmnt/<SID> file system
Performing the RKS • RKS for each SAP instance comprises the following steps • Prepare the instance
– Isolate the instance from any processing – Prevent direct logon, background processing, spooling etc. – Protect the transport system – adjust communica;on system in TMS
• Restart the isolated instance – sapcpe will copy the new kernel from /sapmnt/<SID>/exe to the instance
executable dircetory
• Execute saproot.sh as root • Ac;vate the instance
– Reverse all the isola;on steps above
Monitoring the RKS
• The RKS can be monitored in SM51
• When all applica;on instances have been restarted, the dormant ERS should be restarted, the SCS cluster failed over and the remaining dormant ERS restarted
Performing the RKS on SCS
Thank-‐you