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