Using local media first with Fedora and Yum

With CentOS, if you have the DVD or ISO install image on your CentOS system, just disable the [base] repo in /etc/yum.repos.d/CentOS-Base.repo and enable [c5-media] repo in /etc/yum.repos.d/CentOS-Media.repo and point baseurl= to the right location where the ISO or DVD is mounted (baseurl=/media/PATH-TO-DVD).

This works out great as the CentOS [base] repo and the DVD have the identical contents.

However, with Fedora 7 and newer, this is not the case and things are a bit messy. The contents of the [fedora] repo in /etc/yum.repos.d/fedora.repo have Everything in Fedora since the Core split was dropped, which is a huge amount of packages than ever ship on the DVD.

So, how to use local [InstallMedia] first, while still searching the [fedora] repo, and still get [updates]? The answer is to use yum priorities.

Install this yum plug-in package:
yum install yum-priorities

Once this is installed, use a new priority= option with any repo with conflicting or duplicate packages. In this case we want:
priority = 1 [InstallMedia]
priority = 1 [updates]
priority = 2 [fedora]

This means [InstallMedia] and [updates] are the highest priority. [updates] will win out over [InstallMedia] as it will have newer version numbers. [InstallMedia] will win out over [fedora] as it has a higher priority value (lower number). The exception where packages will be installed from [fedora] is when [InstallMedia] doesn't have it (remember "Everything") and [updates] doesn't contain anything newer.

So the edits needed are:
/etc/yum.repos.d/fedora.repo

Under [fedora] add:
priority=2

Edit:
/etc/yum.repos.d/fedora-updates.repo

Under [updates] add:
priority=1

Finally, copy from the DVD or mounted DVD ISO:
cp /media/DVD/media.repo /etc/yum.repos.d/

Edit /etc/yum.repos.d/media.repo which contains the [InstallMedia] repo to add:
priority=1
baseurl=file:///PATH-TO-DVD/
PATH-TO-DVD should replaced with /media/WHATEVER or where ever the ISO is mounted.

In my case, I have this in my /etc/fstab to mount the ISO on boot:

/storage/f12/Fedora-12-i386-DVD.iso     /storage/f12/dvd        iso9660 ro,user,loop    1 1

So my /etc/yum.repos.d/media.repo has added:
priority=1
baseurl=file:///storage/f12/dvd/

Now just reset yum's info and install away:
yum clean all

So for a test, I will install a few packages, which will show all 3 repos being used:

# yum install openoffice.org-writer kdegames frozen-bubble
Loaded plugins: fastestmirror, presto, priorities, refresh-packagekit, verify
...
Dependencies Resolved

===================================================================================================================================
 Package                                      Arch                Version                          Repository                 Size
===================================================================================================================================
Installing:
 frozen-bubble                                i686                2.2.0-4.fc12                     updates                    20 M
 kdegames                                     i686                6:4.3.4-1.fc12                   updates                    41 M
 openoffice.org-writer                        i686                1:3.1.1-19.14.fc12               InstallMedia              143 k
Installing for dependencies:
 kde-filesystem                               noarch              4-30.fc12                        InstallMedia               45 k
 kde-settings                                 noarch              4.3-15.1                         updates                    41 k
 kdegames-libs                                i686                6:4.3.4-1.fc12                   updates                   1.1 M
 kdelibs                                      i686                6:4.3.4-3.fc12                   updates                    11 M
 kdelibs-common                               i686                6:4.3.4-3.fc12                   updates                   765 k
 openoffice.org-brand                         i686                1:3.1.1-19.14.fc12               InstallMedia              384 k
 openoffice.org-core                          i686                1:3.1.1-19.14.fc12               InstallMedia               81 M
 openoffice.org-opensymbol-fonts              noarch              1:3.1.1-19.14.fc12               InstallMedia              171 k
 openoffice.org-ure                           i686                1:3.1.1-19.14.fc12               InstallMedia              2.5 M
 openoffice.org-writer-core                   i686                1:3.1.1-19.14.fc12               InstallMedia              5.3 M
 perl-SDL                                     i686                2.1.3-11.fc12                    fedora                    313 k

Transaction Summary
===================================================================================================================================
Install      14 Package(s)
Upgrade       0 Package(s)

Total download size: 165 M

As you can see, a huge amount will not need to be downloaded from the internet as they will come from the local [InstallMedia] (all of the OOo packages). However, there are still many packages from [updates] which are needed, and one package from [fedora].

To quickly see the priorities of repos, use this bit of code:

$ cat /etc/yum.repos.d/*.repo | sed -n -e "/^\[/h; /priority *=/{ G; s/\n/ /; s/ity=/ity = /; p }"  | sort -k3n
priority = 1 [InstallMedia]
priority = 1 [updates]
priority = 2 [fedora]

As a side note, the default priority is 99. So, if you forget to give [updates] priority 1 it will default to 99. That will mean that [fedora] or [InstallMedia] will have a preferred priority and actually downgrade any updates you already have and/or prevent them from being installed in the future.

There is newer cost= option as of Fedora 9. However, as I support both RHEL/CentOS 5 systems and Fedora, I'm sticking with priority= which works with both RHEL/CentOS and Fedora.