Fedora can be upgraded in place say from Fedora 34 to Fedora 35. Which is particularly useful since they come out with new versions every 6 months or so. This does require a reboot or two so you may have to schedule a maintenance window. Note that this process does take some disk space since it is downloading all of the packages for the new version of the OS. I usually find 3 Gig of free space to be sufficient. You can reclaim disk space by deleting ZFS snapshots, or compressing rotated logs files.
- Make sure the existing OS is fully upgraded.
dnf update --refresh
- Install the dnf system upgrade plugin.
dnf install dnf-plugin-system-upgrade
- Download the packages for updating to the new version.
dnf system-upgrade download --releasever=<new release version>
- Have dnf reboot and install the new packages.
dnf system-upgrade reboot
When the system reboots it should go into the upgrade install automatically.
- After the system reboots you will be running the new release but you will still be booted on the kernel from the old release. So login and rebuild the grub configuration to make the new kernel first in the list.
grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
- Reboot again so that you are booted on the new release kernel.
- Remove the kernel from the old release and rebuild you grub.cfg again.