Server - Minor Version Upgrade (Y Upgrade)
You can upgrade SUSE Manager to the next minor version using either the YaST online migration tool or the Zypper command line tool. This is often referred to as a product migration, service pack migration, or SP migration. This procedure does not replace the server with an updated copy. It is an in-place upgrade.
The upgrade from version 4.0 to 4.2 will also upgrade the base OS from SLES 15 SP1 to SLES 15 SP3, and the PostgreSQL database from version 10 to 13 with an additional step. For more information about the database upgrade, see Database Migration from Version 10 or 12 to 13.
Upgrades should be run from a text console, rather than a graphical interface like GNOME. If you are logged into a GNOME session running on the machine you are going to migrate, you will need to switch to a text console. This does not apply if you are logged in from a remote machine (unless you are running a VNC session with GNOME).