First of all this update takes more time. So assume that you will need approximately 30 minutes for your server (in rare cases it took 60 minutes).
I have upgraded several environments and I want to share my experiences.
Some environments needed an additional update before "Product Upgrade".
Product Upgrade recommends to run "/opt/novell/product_upgrade/prepare.sh". Do not forget this! Your server will be automatically restarted after this activity.
After restart you will be able to run "Product Update". But you have to re-enter your registration key. I ended up in two situations
I was able to enter a registration key.
A dialog for registration key never appeared. So open a private window within your browser or use another browser!
I checked customer entitlements and detected in many cases that there is no "txt" file containing a Suse registration key. A "rehost" solved all incidences.
Now your update can be started. Because your appliance will be upgraded to Sles15SP3 it will take some time. But none of my upgrades failed ...
So if you consider to upgrade (read my last sentence!) - good luck! I am pretty sure you will succeed.
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