How to upgrade from SLES 11 SP3 to SLES 15 SPx

I’m new to SLES OS, could you help me on below requests.
How to upgrade from SLES 11 SP3 to SLES 15 SP3? Current server is diskless boot running with SAP Hana
Can we upgrade from SLES 11 SP3 to SLES 15 SP3 or higher without damage existing data?
How to create NetBoot SLES15 initrd’s?
Thank you in advance.
Regards
Naresh

Hi and welcome to the Forum :slight_smile:
You would have to get to SLES 11 SP4 (LTSS) first, see https://documentation.suse.com/sles/15-SP2/html/SLES-all/cha-upgrade-paths.html#sec-upgrade-paths-supported

Ref: https://documentation.suse.com/sles/15-SP2/html/SLES-all/book-sle-upgrade.html

Hi Malcolmlewis,
Thank you very much for your help, i will go through the documentation and let you know if i have any doubt.
if i upgrade from SLES 11 SP3 to SP4 to SLES15-SP2 – is existing application data overwrite or no impact to data? could you confirm please

Thanks and Regards
Naresh

Hi Malcolmlewis,
Our servers are running with disk less boot, OS in NFS. could you help to provide suitable document for upgrade SELS in diskless boot environment?

Thanks and Regards
Naresh