From Fedora Project Wiki

Brianjmurrell: In step 2, dnf update --refresh is it really necessary to upgrade every package on a system you are about to upgrade to new versions of those same packages anyway? I could certainly see wanting to update a subset of packages covering dnf and rpm perhaps but why do I need to update things like my desktop packages to latest on release N when I only going to turn around and update that N+1 right away?

Kparal (talk): The point is to update important system tools like dnf, rpm, systemd, dracut, grub, etc, because there might be (and sometimes really is) some bug that badly interferes with the upgrade procedure and an update fixes it. So if you haven't updated in a long time, this command makes sure you have it fixed before you attempt to upgrade. If you use and update your system regularly, the amount of updates should be quite small, even though it includes all packages. If, for some reason, you don't want to update everything, you don't need to, as long as you make sure you update all the important packages (which can affect the upgrade). However, it can be quite tricky to find out which those are. If you want to go this route, I'd rather recommend you to exclude some known and large desktop apps (like libreoffice and firefox) than to try to make a list of every important low-level tools to update (you're very likely to miss something this way).

Not quite what happened.

  • The use of repoquery requires installation of a plugin. It would be helpful to explain this. (I already had the other plugin, for which instructions are provided, but not this one.)
  • I did not find any duplicates, despite having multiple kernels installed.
  • grub.cfg was not updated with the new release's kernel. (grub.cfg is never updated automatically on my system for reasons I don't understand.)
  • It would be helpful to mention that the use of --best can provide helpful information if the download stage fails for other reasons, such as conflicts between packages which dnf thinks it need to install i.e. over-satisfied dependencies, and not just unsatisfied dependencies.

[Off-topic but it seems outrageous that I have to have a telephone number to leave these comments. I'm not especially unwilling to give one, I just don't really have one which is suitable to give.]

--Cfr42 (talk) 23:26, 21 December 2015 (UTC)

Kparal (talk): Hey Cfr42, repoquery is in dnf-plugins-core, which should be installed by default. Multiple kernels are no longer shown in duplicates, you're right, wiki adjusted. For grub.cfg, please file a bug or find some help. Regarding --best, I believe the output should be the same (dependency errors should be printed out in both). If you have an output showing an important difference between --best and no --best using the latest dnf-plugin-system-upgrade, please link it here and I'll look at it, thanks.

26 isn't available as a target yet

Fedora 26 is not branched yet. At least --releasever=26 doesn't function yet. --Taw (talk) 21:47, 11 February 2017 (UTC)

Kparal (talk): Yes, that is correct. See Releases/26/Schedule to learn when F26 gets branched.

Rawhide needs to include additional instruction

You need to install the fedora-repos-rawhide before you start this process, and apparently. "file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-rawhide-x86_64" ... apparently that file doesn't exist anywhere and you have to --nogpg

--Taw (talk) 21:47, 11 February 2017 (UTC)

Please please don't use nogpgcheck. Thats just a bad idea. The rawhide file should be a link to the latest key version. There's a bug on fedora-repos to fix this. In the mean time I added some info to work around this issue in the page.

--kevin

some tips

1 . you may add keepcache=1 to /etc/dnf/dnf.conf , to avoid download all packages again, if first download fail and you need remove some packages with dnf .

2. dnf update fedora-repos.noarch , fedora 24 and 25 (fedora-repos-25-4.noarch) have important fixes to gpg verification works correctly on dnf