Weeks ago Fedora 26 was released, and as I use fedora linux on all my laptop computers I just decided to upgrade to the lastest stable version. This is the procedure I used on both work and home notebooks to upgrade Fedora 25 to Fedora 26, and it worked perfectly.
Upgrade Fedora 25 to Fedora 26
If you want to run this fedora upgrade, you can do it using sudo, otherwise this can be safely ran as root user.
1. Backup all your critical data into a external drive, Dropbox or somewhere safe.
2. Upgrade your Fedora distro by using the normal method using dnf:
dnf upgrade --refresh
3. Install dnf-plugin-system-upgrade app:
dnf install dnf-plugin-system-upgrade
4. Download the Fedora 26 release packages:
dnf system-upgrade download --refresh --releasever=26
If you are upgrading from previous versions like Fedora 24 (fc24), the recommended method to avoid compatibility issues is to first upgrade to fedora 25, and then from 25 to 26.
DNF verifies the integrity of all downloaded packages using gpg checking, you can optionally disable this security check by using the –nogpgcheck parameter (not recommended).
If any system packages have unsatisfied dependencies the upgrade process will be terminated and you will not be able to continue. In order to fix this you will have to let Fedora erase those unmatched packages by adding the follwoing, like this:
5. Launch the upgrade process:
dnf system-upgrade reboot
This will reboot the Fedora system, after that you will boot Fedora normally but the first thing you will notice is the upgrade process that will continue from that point until it finished installing everything.
Wait again until the upgrade process finishes, then reboot your computer to finish and it should boot normally asking for the Linux user login session.
That’s all, at this time you should be able to upgrade Fedora 25 to Fedora 26 without any issues.
If you have post-upgrade issues, it is highly recommended to visit the official docs for upgrade problems from Fedoraproject.org