18.3. Troubleshooting and Cleanup

⁠18.3. Troubleshooting and Cleanup

In the event of an unsuccessful upgrade, try the following:

Third party repositories can prevent an upgrade. They might not yet be available for the version of Fedora you are upgrading to, and some might not automatically change to reflect the update. You can list the enabled repositories with this command:
```
            yum repolist
```
To disable a repository, use this command:
```
             yum-config-manager --disable <repo-name> 
```
To enable the repository again after the upgrade, use this command:
```
             yum-config-manager --enable <repo-name> 
```
After the upgrade, you may have to reconfigure some third party repositories or reinstall the software they provide to get the correct version for Fedora 20.
Check the upgrade log at /var/log/fedup.log. You can open this file in your favorite editor, or by executing the command less /var/log/fedup.log from a terminal. The file is large, but any problems will usually be towards the end.
Consult the Fedora 20 Common Bugs page at http://fedoraproject.org/wiki/Common_bugs for upgrade related issues.
Upgrades can sometimes affect GRUB packages. Unlike other software, GRUB is installed only during installation or when manually reinstalled. It is suggested that after the upgrade is complete, the GRUB binary should be manually updated. The configuration can be regenerated if needed.
To upgrade GRUB on BIOS systems, first identify your boot drive. On a system with a single drive, this will be /dev/sda. Install the GRUB binary to the drive's Master Boot Record with the following command:
```
                grub2-install /dev/sda
```
To update the GRUB configuration on BIOS systems, use following command:
```
                grub2-mkconfig -o /boot/grub2/grub.cfg
```
Updating GRUB on UEFI systems should not be necessary, but if required, the configuration can be updated with this command:
```
                grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
```
Differences in package versions can lead to conflicts between the system's installed package set and the updates to be installed. These issues can interfere with upgrading to the next Fedora release, or interfere with normal package updates, especially if a testing repository is used ( such as with a pre-release ) then disabled.
To sync packages to the versions available for your Fedora release, before or after the upgrade, use this command:
```
                yum distro-sync
```
New versions of packages or package groups can have different dependencies from those they replace. Packages on the system that were installed to fulfull dependencies that are no longer required are known as leaves.
To identify leaves, use this command:
```
                package-cleanup --leaves
```
Some packages may have been available in previous releases, but not in the release you have upgraded to. These are known as orphans.
To identify orphans, use this command:
```
                package-cleanup --orphans
```
package-cleanup can also be used for duplicate packages and old kernels, and offers more options. Refer to man package-cleanup for more information.
Be careful when cleaning packages!
Some packages may be listed by package-cleanup that you might use. For example, you might use a Python library in scripts you have written, but it may not have any packaged software that depends on it. Be sure that you do not need a package before you remove it. In most cases, it will do no harm to leave the package installed.
Duplicates or conflicts that prevent updates can be identified with package-cleanup, but yum distro-sync should be used first.
Although SELinux policy changes are applied during package updates, the filesystem can be relabeled if required. If you experience more SELinux denials after an upgrade, or otherwise need to relabel the system, use the following command, then reboot the system. The relabel will take some time, so be patient.
```
                touch /.autorelabel
```
Relabeling can also be done selectively with the restorecon utility. For example, this command can correct labels some files used by the squid caching proxy:
```
                restorecon -R /var/cache/squid/
```
Once you have rebooted your system after performing an upgrade, you should also perform a manual system update. Consult Section 17.1, “Updating Your System” for more information.