IMPORTANT:To upgrade an OES VM paravirtualized guest to OES 2018 or later, you must install using files on the network. Physical media upgrades and using ISO image files are not supported methods.
Performing a down-server upgrade on a Xen VM guest is very much like upgrading a physical machine
Make sure you follow all of the applicable instructions and guidelines in Section 5.2, Planning for the Upgrade and Section 5.3, Meeting the Upgrade Requirements.
In Virtual Machine Manager, shut down the OES VM guest that you are upgrading.
Enter the command vm-install --upgrade at the terminal console.
On the Create a Virtual Machine page, click Forward.
Select I need to upgrade an existing operating system if it is not selected, then click Forward.
Select Supported version of SLES for OES, then click Forward.
In the Managed Virtual Machines list, select the VM guest you are upgrading.
In the Network URL field, type the URL to your network-based installation source, then click Upgrade.
On the Welcome page, agree to the license and click Next.
For instructions on the rest of the upgrade process, go to Section 5.0, Upgrading to OES 2018 SP3 and continue from there.