===== Online upgrade SLE 15 SP with DVD =====
   * Insert DVD on machine
   * Backup /etc/zypp/repos.d
   * Remove /etc/zypp/repos.d
   * Execute Yast -> Software -> Software Repositories -> Add -> Use DVD option
   * Select the repositories that you need
   * Copy SLE-15*SP*-15.*.repo file to the new /etc/zypp/repos.d
   * Replace SPx and 15.x with the correct version... for example SP4 to SP5 and 15.4 to 15.5
   * Run zypper refresh -s -f
   * Finally run zypper dup -D --no-allow-vendor-change --no-recommends #that will test everything is OK
   * Perform zypper dup --no-allow-vendor-change --no-recommends  to complete the upgrade
   * Reboot the vm
   * Tadaaaaa!

==== Resources ====
  * https://documentation.suse.com/sles/15-SP5/html/SLES-all/cha-upgrade-paths.html