Upgrading RHEL 6.10 to RHEL 7.9 for SAP Application requirements
Problem statement:RHEL 6.10 Support will be going to end and SAP application has to be run for business requirement with OS upgraded version without impacting any of the existing data.The same VM resources(CPU,DISK and memory) to be used.
Technology Used: VMWARE,Redhat,Rear
Prerequisite steps :old OS image backup has taken using REAR tool in the ISO format.Snapshot taken on the VM level.Run the redhat-preupgrade assessment tool to identify risk on dependency of application and OS related packages.
Solution : Copied the RHEL 7.9 ISO image and mapped as CDROM in the Vcenter.Disabled the RHEL 6 repository.we upgraded using redhat-upgrade tool by pointing local mounted cdrom.OS is upgraded and existing data filesystem are maintained with ext4.After upgrade SAP application was not able to bring up due to library file is not supporting with the upgraded RHEL 7.9 version.Dependency library file(S0) is installed with the necessary packages.
Dont’s :Don’t mount ISO images as NFS share and try to upgrade the OS.It will fail and won’t upgrade.
Post patching wat kind of issues we face and how to fix it.
1. suppose server doesnt up post patching what steps to be followed.
2. post application patching if OS binary and application binary doesnt
match what steps to be followed