> Basically I am attempting a Red Hat 7.2 -> CentOS-2 upgrade. So far it > has worked like a charm. The problem is though that yum (no doubt by > design) will not downgrade packages to the CentOS versions. yep. True. > The problem is that some old RPMs have 72 in the release (for Red Hat > 7.2) and the newer package as 21 in the release (For Enterprise Linux > 2.1). Some others are updates to 7.2 which increased the version number > where as 2.1 got a backported fix and increased release number. which is what happens when something branches earlier. > Is there a way to make yum always select a particular Vendor or > Distribution? What about using yum to do an explicit downgrade > "yum install mypackage-version-oldrelease"? not for yum 1.0.X or 2.0.X. 2.1.x can but it's not going to work on a rhl 7.2 or rhel2.1 one system. > Also, this is an rpm question, does anyone know if I can do > "rpm --erase redhat-logos" and "rpm -i centos-logos" at the same time? rpm --erase --nodeps redhat-logos ; rpm -i centos-logos they'll only be logo-free for a brief moment :) > If I put an obsoletes: tag into centos-logos will yum do that for me? > Is that a good idea? yum upgrade will do obsoletes, yes. > At the moment I have a bash script which trys to work out the downgrade > rpm commands but I can not check dependencies. Any other suggestions, > tips or tricks would be appreciated. it's not hard to do a version comparison on any package in the tree versus those installs and you could do: rpm -Uvh --oldpackage stuff -sv