leapfrog online upgrade can succeed

Everywhere is recommended to upgrade only one release version at a time, because only one at a time is “supported”. This thread is to report there is apparently little danger in skipping. I haven’t kept track, but I’m guessing out of my 15 current 15.1 installations, 5-6 times I upgraded directly to 15.1a or 15.1b or 15.1 final from releases older than 15.0. With 15.0 I jumped from as far back as 13.1. Yesterday I upgraded a TW installation that hadn’t been upgraded in over 7 months. An hour ago I finished another hiccup-free jump, this time from 42.2/KDE3 to 15.1/KDE3, with ancient Radeon X600 (1002:5b62) video.

My technique includes disabling all optional repos, “solver.onlyRequires = true” and “commit.downloadMode = DownloadAsNeeded” in /etc/zypp/zypp.conf, then beginning the upgrade by preceding zypper dup with the same script I use for preceding normal updates, designed to upgrade the package management stack before anything else:

# /usr/local/zypstart
zypper -v in --download-in-advance zypper libzypp libsolv-tools rpm openSUSE-release
zypper -v in --download-in-advance device-mapper dmraid glibc multipath-tools mdadm systemd udev

Most times when starting zypper dup I strike g then home and peruse the plan, quite often aborting in order to add or remove locks and/or selected packages.

I suspect minor versions can be skipped with less risk if the system is very simple and uncomplicated.
I’d guess that if applications like LAMP or any RDBMS is installed, then it probably is critical to not skip even minor versions, and even so should be prepared for application failure and recovery.