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documentation.suse.com / SUSE Linux Enterprise Desktop Documentation / Upgrade Guide / Preparing the upgrade
Applies to SUSE Linux Enterprise Desktop 15 SP3

3 Preparing the upgrade

Before starting the upgrade procedure, make sure your system is properly prepared. Among other things, preparation involves backing up data and checking the release notes. The following chapter guides you through these steps.

3.1 Make sure the current system is up-to-date

Upgrading the system is only supported from the most recent patch level. Make sure the latest system updates are installed by either running zypper patch or by starting the YaST module Online-Update.

3.2 Read the release notes

Find a list of all changes, new features, and known issues in the release notes. You can also find the release notes on the installation media in the docu directory.

The release notes usually only contain the changes between two subsequent releases. If you are skipping one or more Service Packs, check the release notes of the skipped Service Packs as well.

Check the release notes to see whether:

  • your hardware needs special considerations;

  • any used software packages have changed significantly;

  • special precautions are necessary for your installation.

3.3 Make a backup

Before upgrading, back up your data by copying the existing configuration files to a separate medium (such as tape device, removable hard disk, etc.). This primarily applies to files stored in /etc and some directories and files in /var and /opt. You may also want to write the user data in /home (the HOME directories) to a backup medium.

Back up all data as root. Only root has sufficient permissions for all local files.

If you have selected Update an Existing System as the installation mode in YaST, you can choose to do a (system) backup at a later point in time. You can choose to include all modified files and files from the /etc/sysconfig directory. However, this is not a complete backup, as all the other important directories mentioned above are missing. Find the backup in the /var/adm/backup directory.

3.4 Listing installed packages and repositories

You can save a list of installed packages, for example when doing a fresh install of a new major SLE release or reverting to the old version.


Be aware that not all installed packages or used repositories are available in newer releases of SUSE Linux Enterprise. Some may have been renamed and others replaced. It is also possible that some packages are still available for legacy purposes while another package is used by default. Therefore some manual editing of the files might be necessary. This can be done with any text editor.

  1. Create a file named repositories.bak.repo containing a list of all used repositories:

    # zypper lr -e repositories.bak
  2. Also create a file named installed-software.bak containing a list of all installed packages:

    # rpm -qa --queryformat '%{NAME}\n' >
  3. Back up both files. The repositories and installed packages can be restored with the following commands:

    # zypper ar repositories.bak.repo
    # zypper install $(cat installed-software.bak)
    Note: Number of packages increases with an update to a new major release

    A system upgraded to a new major version (SLE X+1) may contain more packages than the initial system (SLE X). It will also contain more packages than a fresh installation of SLE X+1 with the same pattern selection. Reasons for this are:

    • Packages were split to allow a more fine-grained package selection. For example, 37 texlive packages on SLE 11 were split into over 3000 packages on SLE 15.

    • When a package has been split, all new packages are installed in the upgrade case to retain the same functionality as with the previous version. However, the new default for a fresh installation of SLE X+1 may be to not install all packages.

    • Legacy packages from SLE X may be kept for compatibility reasons.

    • Package dependencies and the scope of patterns may have changed.

3.5 Disable the LTSS extension

If you upgrade a SUSE Linux Enterprise Desktop system with Long Term Service Pack Support (LTSS) to a version that is still under general support, the upgrade will fail with the error No migration available. This happens because zypper migration tries to migrate all repositories , but there is no LTSS repository for the new version yet.

To fix this issue, disable the LTSS extension before the upgrade.

  1. Check if the LTSS extension is enabled:

    > sudo SUSEConnect --list-extensions | grep LTSS
    SUSE Linux Enterprise Server LTSS 12 SP4 x86_64 (Installed)
    Deactivate with: SUSEConnect -d -p SLES-LTSS/12.4/x86_64
  2. Disable the LTSS extension with the command from the SUSEConnect output above:

    > sudo SUSEConnect -d -p SLES-LTSS/12.4/x86_64
    Deregistered SUSE Linux Enterprise Server LTSS 12 SP4 x86_64
    To server: https://scc.suse.com/
  3. Verify the LTSS repository is no longer present with zypper lr.

3.6 Shut down virtual machine guests

If your machine serves as a VM Host Server for KVM or Xen, make sure to properly shut down all running VM Guests prior to the update. Otherwise you may not be able to access the guests after the update.

3.7 Adjusting your SMT client setup

If the machine you want to upgrade is registered as a client against an SMT server, take care of the following:

Check if the version of the clientSetup4SMT.sh script on your host is up to date. clientSetup4SMT.sh from older versions of SMT cannot manage SMT 12 clients. If you apply software patches regularly on your SMT server, you can always find the latest version of clientSetup4SMT.sh at <SMT_HOSTNAME>/repo/tools/clientSetup4SMT.sh.

In case upgrading your machine to a higher version of SUSE Linux Enterprise Desktop fails, deregister the machine from the SMT server as described in Procedure 3.1. Afterward, restart the upgrade process.

Procedure 3.1: Deregistering a SUSE Linux Enterprise client from an SMT server
  1. Log in to the client machine.

  2. The following step depends on the current operating system of the client:

    • For SUSE Linux Enterprise 11, execute the following commands:

      > sudo suse_register -E
      > sudo rm -f /etc/SUSEConnect
      > sudo rm -rf /etc/zypp/credentials.d/*
      > sudo rm -rf /etc/zypp/repos.d/*
      > sudo rm -f /etc/zypp/services.d/*
      > sudo rm -f /var/cache/SuseRegister/*
      > sudo rm -f /etc/suseRegister*
      > sudo rm -f /var/cache/SuseRegister/lastzmdconfig.cache
      > sudo rm -f /etc/zmd/deviceid
      > sudo rm -f /etc/zmd/secret
    • For SUSE Linux Enterprise 12, execute the following commands:

      > sudo SUSEConnect --de-register
      > sudo SUSEConnect --cleanup
      > sudo rm -f /etc/SUSEConnect
      > sudo rm -rf /etc/zypp/credentials.d/*
      > sudo rm -rf /etc/zypp/repos.d/*
      > sudo rm -f /etc/zypp/services.d/*
  3. Log in to the SMT server.

  4. Check if the client has successfully been deregistered by listing all client registrations:

    > sudo smt-list-registrations
  5. If the client's host name is still listed in the output of this command, get the client's Unique ID from the first column. (The client might be listed with multiple IDs.)

  6. Delete the registration for this client:

    > sudo smt-delete-registration -g UNIQUE_ID
  7. If the client is listed with multiple IDs, repeat the step above for each of its unique IDs.

  8. Check if the client has now successfully been deregistered by re-running:

    > sudo smt-list-registrations

3.8 Disk space

Software tends to grow from version to version. Therefore, take a look at the available partition space before updating. If you suspect you are running short of disk space, back up your data before increasing the available space by resizing partitions, for example. There is no general rule regarding how much space each partition should have. Space requirements depend on your particular partitioning profile and the software selected.

Note: Automatic check for enough space in YaST

During the update procedure, YaST will check how much free disk space is available and display a warning to the user if the installation may exceed the available amount. In that case, performing the update may lead to an unusable system! Only if you know exactly what you are doing (by testing beforehand), you can skip the warning and continue the update.

3.8.1 Checking disk space on non-Btrfs file systems

Use the df command to list available disk space. For example, in Example 3.1, “List with df -h, the root partition is /dev/sda3 (mounted as /).

Example 3.1: List with df -h
Filesystem     Size  Used Avail Use% Mounted on
/dev/sda3       74G   22G   53G  29% /
tmpfs          506M     0  506M   0% /dev/shm
/dev/sda5      116G  5.8G  111G   5% /home
/dev/sda1       39G  1.6G   37G   4% /windows/C
/dev/sda2      4.6G  2.6G  2.1G  57% /windows/D

3.8.2 Checking disk space on Btrfs root file systems

On a Btrfs file system, the output of df can be misleading, because in addition to the space the raw data allocates, a Btrfs file system also allocates and uses space for metadata.

Consequently a Btrfs file system may report being out of space even though it seems that plenty of space is still available. In that case, all space allocated for the metadata is used up. For more information refer to man 8 btrfs-filesystem and https://btrfs.wiki.kernel.org/index.php/FAQ.

When using Btrfs for root file systems on your machine, make sure there is enough free space. Check the available space on all mounted partitions. In the worst case, an upgrade needs as much disk space as the current root file system (without /.snapshot) for a new snapshot.

The following recommendations have been proven:

  • For all file systems, including Btrfs, you need enough free disk space to download and install big RPMs. The space of old RPMs is only freed after new RPMs are installed.

  • For Btrfs with snapshots, you need as a minimum as much free space as your current installation takes. We recommend having twice as much free space as the current installation.

    If you do not have enough free space, you can try to delete old snapshots with snapper:

    # snapper list
    # snapper delete NUMBER

    However, this may not help in all cases. Before migration, most snapshots occupy only little space.