On 2015-11-07 08:07, Andrei Borzenkov wrote:
07.11.2015 02:34, Carlos E. R. пишет:
I also wonder, how "zypper dup" or DVD upgrade handles the downgraded packages.
Nicely, it is expected.
Nitpicking - all that zypper does is equivalent of "rpm -i --force --replacepkgs" which will install any version over any version. Whether RPM can actually be installed depends on changes between these two versions. There are known file layout changes that cannot be handled on RPM level (like replacing directory with symlink) - such changes must be caught by scripts. But old RPM version is not aware of layout change in new version of course ... Another example is splitting of single service in several independent ones, where old RPM cannot of course know it should enable old service.
The "old" rpm, being in fact built after the "new" rpm, could know about it ;-)
This is different from upgrade where new RPM version can be prepared to handle such cases.
Well, right. However, specially in the case of DVD upgrade, you can code anything needed in the "upgrade distro" section ;-) Whether it is done or not, I have no idea. Years ago, in SuSE times, there were release notes that specified the upgrade caveats, what would not work and the admin had to handle himself. What was different on each release. Anyway, I understand that upgrade was tested by openqa, so it should work nicely. I haven't being able to try myself and verify. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)