Upgrading Fedora Linux 20 (Heisenbug) to 21 & 22

Although I've recently switched to Ubuntu for my work, I'm still using Fedora (dual-boot with Windows 7) on my home workstation. I've been running Fedora 20 ("Heisenbug", horrible name) since mid-2014 so my installation was pretty aged - and with the release of Fedora 22 in May has been end-of-life'd since June this year. So it was definitely time for an update.

When I moved previously to F20 I did a fresh install (although I was able to keep my /home from the previous F16 installation). However this time I decided to go with an upgrade using FedUp (FEDora UPgrader), especially attractive since it promised to also update the installed packages - meaning that I wouldn't need to start over again with installing and configuring all the applications and tools that I use.

The upgrade procedure is covered pretty comprehensively in the FedUp documentation at https://fedoraproject.org/wiki/FedUp. As I was two releases adrift I decided to perform the upgrade twice (i.e. going from F20->F21->F22) as recommended. This seemed the safest route, especially given two of the significant changes introduced with each of these realeases, specifically:

• Fedora 21 introduced the idea of "products", which can be thought of as sub-releases specifically targeted for particular user needs. When upgrading from F20, you need to specify which product sub-release you're moving to: the available options are "workstation" (which looks like the best choice for desktop use), "server" or "cloud".
• Fedora 22 switched from the old yum package manager to a newer version called dnf ("dandified yum") - see https://fedoraproject.org/wiki/Changes/ReplaceYumWithDNF

(As an aside, another change is that from F21 the releases will no longer have names - so F21 is just "Twenty One", and F22 is "Twenty Two".)

The upgrade process for each revision was then:

1. Install the fedup package:

sudo yum install fedup

2. Perform all updates & backup your system (my preference is still for CloneZilla Live)

3. Perform a network-based upgrade (the recommended method over e.g. upgrading from an ISO image):

sudo yum update fedup fedora-release

sudo fedup --network 21 --product=workstation

(As noted earlier, for F20-to-F21, you need to specify which product line you are moving to - hence the --product option above. For F21-to-F22 the second line can be reduced to simply sudo fedup --network 22)

4. Reboot and select "System Upgrade (fedup)" from the GRUB menu, which will boot into an upgrader environment and then churn through all the packages. (Note that this can take some time: for F20-to-F21 this has a textual display and for me the screen would go black periodically during this process, however moving the mouse seemed to restore the display. For F21-to-F22 there is a nice graphical progress bar; using F1 toggled between this and the textual display.)

5. If the previous step completes successfully then the system will reboot automatically and there should be an option for the new Fedora version in the boot menu. Select this to boot into the new version and check that it looks as you expect.

At this point the documentation outlines some post-upgrade clean-up actions that need to be performed manually:

1. Rebuild the RPM database:

sudo rpm --rebuilddb
sudo yum distro-sync --setopt=deltarpm=0

2. Install and run rpmconf to identify packages that have more recent versions, and interactively decide what to do for each:

sudo yum install rpmconf

sudo rpmconf -a

(After upgrading to F22 replace the first line with
sudo dnf install rpmconf
However for me when running the subsequent step, rpmconf crashed out with an error about a missing file, so I wasn't able to complete this step.)

Overall the process was pretty painless, and after a week or so I haven't noticed any issues (other than my continued inability to get a working version of Google Chrome - but that problem predates this upgrade), with everything appearing to work at least as well as before.

Also while Fedora 22 looks very much like Fedora 20, there have been some visual tweaks which I feel make it a bit nicer to look at than before (however this is perhaps a personal thing - see Chris Duckett's A month with Fedora 22 leaves me hungry for 23 for a counter-view), and for now I'm enjoying my "refreshed" Fedora experience.