At https://en.opensuse.org/SDB:System_upgrade we can learn, there are 2 ways to upgrade the whole distro.
Live with zypper or offline, booting from DVD.
One sentence there makes me wonder, it´s this:
"It does not do all of the cleanup and maintenance that an offline DVD Upgrade does
What maintenance exactly does the DVD upgrade do, zypper does not do?
I just upgraded from 15.1 to 15.2 using zypper live, the only thing I noticed are a plenty of .rpmnew files in /etc. I usually check those /etc/.rpmnew files manually.
I’m not really sure what was intended with that quoted sentence.
I have tried both methods. And the online upgrade went better, in my opinion. The main difference that I was was this
With the DVD upgrade, a number of package from the packman repo were moved to the openSUSE repos. And, when I was done upgrading, I had to move them back.
With the online upgrade, the packages from packman were mostly moved to the 15.2 packman repos. And everything worked more smoothly.
Yes, when done I ran “rpmconfigcheck” and dealt with a bunch of “*.rpmnew” files.
Interesting, I wasn´t aware of rpmconfigcheck, though it doesn´t have a man page…
I usually deal manually with the *.rpmnew files.
As long as you are upgrading from the previous release, an online upgrade is far better as, for example, mysql databases are not overwritten and most, but not all, configuration changes you may have made are left untouched.
Also, the further you are from the release date, the more packages you have to update after the installation if using the DVD.