With the system upgrade term we mean upgrading the installed system to a new product version.
The offline/online term refers to the system state, it is not about network status or about using remote (HTTP/FTP/...) or local (DVD/disk/...) installation repositories.
At the online upgrade the system is running and the packages are upgraded while the system is in use. At the offline upgrade the system is rebooted into installation medium and the system cannot be used during the upgrade.
The online upgrade can be used for a service pack level upgrade, for upgrading to a new product version the offline upgrade should be used.
It is recommended to install all latest online updates before running the upgrade. The updates might include a fix for the system upgrade.
In all cases it is recommended to backup the old system before doing an upgrade.
- FATE#323163 - YaST: SLES12 to SLES15 migration
SLE-15 Offline Upgrade Workflow
The high level upgrade workflow should include these steps:
- Start the installer
- Select the language/keyboard
- Select the root partition with the system to upgrade
- Display and confirm the license of the new system
- Load the installed products (the base product and all add-ons)
- Load the matching base product from the medium
- Send the the installed products and the product from medium to SCC/SMT
- The response will contain the possible upgrades, some add-ons might be available in multiple versions, user should be able to select which version will be installed
- Ask the SCC/SMT to upgrade the registration to the selected versions, this will add new installation repositories with packages to upgrade
- Switch libzypp into the distribution upgrade mode and run the package solver to select the needed packages for upgrade
- Display the upgrade summary, until this point it is still possible to abort the upgrade and revert the system back into the original system.
- After user confirms the upgrade YaST starts the package installation. After the package upgrade starts it is possible to restore the original system only from a snapshot (if enabled in the system) or from a backup.
- Run the finish clients to adjust the system configuration
- Reboot into the upgraded system
- SCC/SMT will always add all available modules to make sure all SLE12 packages can be upgraded to their SLE15 version
- The system will be upgraded only to the version available on the installation medium. In theory we could upgrade even to a newer version (SP+1), but to limit the QA and the testing scope it is limited only to the base product on the medium.
Not Registered System
If the system is not registered then steps 4. to 9. are skipped and the user can use the provided DVD media for the upgrade. If upgrade via SCC/SMT is still required the system should be rebooted into the old system and registered there.
The Old Medium Based Upgrade
This is basically the same as the upgrade of an unregistered system described above but can be manually forced even for a registered system. The switch will be done via a hidden boot parameter (not displayed in the isolinux boot menu). (Not implemented yet)