Upgrading to SUSE Linux Enterprise Server 16

Perform the following steps before starting the upgrade:

1. Make sure the latest system updates are installed by running zypper patch.

2. Read the release notes. Find the list of all changes, new features and known issues in the release notes.

   Consult the release notes to check whether the following applies:

   • Your hardware needs special considerations

   • Any currently used software packages have changed significantly

   • Your installation requires special precautions

3. Back up your data by copying the existing configuration files to a separate medium (such as a tape device or removable hard disk). This primarily applies to files stored in /etc and some directories and files in /var and /opt.

4. Check the available disk space. If you suspect you are running short of disk space, free up disk space or resize partitions.

5. If your machine serves as a VM Host Server for KVM, properly shut down all running VM Guests prior to the upgrade.

1. Use zypper packages to check for orphaned and unneeded packages.

   1. Orphaned packages are no longer available in any of the configured package repositories. They can no longer get updated and become unsupported.

      For a list of orphaned packages, run:

      > zypper packages --orphaned

   2. Unneeded packages are dependencies of packages that have been installed either explicitly by the user or implicitly as part of a pattern or product, and that have been removed in the meantime. They are usually no longer needed and should be removed, too.

      For a list of unneeded packages, run:

      > zypper packages --unneeded

      

      Tip

      To avoid unneeded packages, use zypper rm with the --clean-deps option.

   3. You can combine both lists into one:

      > zypper packages --orphaned --unneeded

   4. Use these lists to determine which packages are still needed and which can be safely removed.

      

      Warning: Do not remove packages you need

      If packages are renamed or removed from a pattern or product, zypper may no longer consider them explicitly installed and mark them as unneeded, even though they are still crucial for your installation.

      Carefully review the list of packages you are removing.

      To remove all orphaned and unneeded packages with a single command, run:

      > sudo zypper rm $(zypper --no-refresh packages --orphaned --unneeded | gawk '{print $5}' | tail -n +5)

      Exclude a single package or pattern from being uninstalled:

      > sudo zypper rm $(zypper --no-refresh packages --orphaned --unneeded | gawk '{print $5}' | tail -n +5 | grep -v PACKAGE_TO_EXCLUDE)

      Exclude multiple packages defined in a text file, separated by a newline:

      > sudo zypper rm $(zypper --no-refresh packages --orphaned --unneeded | gawk '{print $5}' | tail -n +5 | grep -v -f /PACKAGES/TO/KEEP.txt)

2. Check for any *.rpmnew and *.rpmsave files. When an upgrade includes changes to a default configuration file that has been altered after package installation, instead of overwriting the file, one of these file types is created. While *.rpmnew contains the new default configuration and leaves your altered file untouched, *.rpmsave is a copy of your altered configuration that has been replaced by the new default file.

   If you find any of these files, examine their content and merge desirable changes. You do not need to search the whole file system, only the /etc directory. Use the following command:

   > find /etc/ -name "*.rpmnew" -o -name "*.rpmsave"