Upgrade Fedora 18 to Fedora 19 using an ISO

To upgrade fedora the fedup package must first be installed, which can be accomplished by typing
# yum install fedup

There are three options for sourcing the packages needed for upgrade - using a network repository (--network) , a local ISO (--iso) file or a local device (--device) (hard drive, optical disk etc.).

In order to use an ISO file, it needs to exist locally on the filesystem of the system to be upgraded. The documentation is written as if that file is /home/user/fedora19dvd.iso but you will need to replace all instances of that path with the actual path of the ISO. Updates will be pulled in if you have network access on the machine to be upgraded.

1. Download the Fedora 19 ISO appropriate for the arch that you are running
For the sake of example, we will assume that the ISO exists at /home/user/fedora19dvd.iso but it can be anywhere in the filesystem as long as you alter the path below to reflect the actual location of the ISO. Make sure you have downloaded Fedora DVD ISO image otherwise you will get the following error -
setting up repos...
Error: can't get boot images.
The 'fedupiso' repo was rejected by yum as invalid.
The given ISO probably isn't an install DVD image.

2. Start the upgrade prep by executing the following command
# fedup-cli --iso /home/user/fedora19dvd.iso
However, you can perform an unattended upgrade by typing
# fedup-cli --reboot --iso /home/user/fedora19dvd.iso
The extra switch will reboot the system automatically after the first step has completed.

3. Once the preparations have completed, check the /var/log/fedup.log file if any errors show up in the output from fedup-cli.

It is also possible to specify more than one source. For example, using fedup --iso --network 19 will perform the upgrade using an ISO image in a local directory, while pulling in any available updates from the repositories.

The tutorial in LinuxBSDOS explains superbly about various methods of upgrading and how to progress in each method.

If you decide not to proceed in the middle of the upgrade execute the following command.
# fedup-cli --clean

The following screenshot shows the update process in sequence.