On Tuesday, June 07, 2011 07:40:26 AM Kwan Lowe wrote:
Not sure if this will help, but I went the other way from CentOS to RedHat by grabbing a list of packages with "rpm -qa", cleaning up the package names a bit, installing a base RedHat based on the same update level, then "yum update" or "yum install"ing from the list of packages. Next I diffed the configuration directories and manually moved the changed files. Finally just backed up/restored the database and application LVMs (dd/gzip the entire partition).
Whee, that's a lot of work. With EL6 you have 'yum distro-sync' at your beckon call; a patch to add a 'distro-sync full' exists that goes as far as checking checksums, which probably has a greater chance of working correctly.
On an EL6 it should be as simple as changing the repositories and issuing yum distro-sync (with some rhn-specific steps depending on the direction of the cross-grade, though). But I say 'should' for a reason, as I've not tried. Yet. I likely will try this once C6 is out, since I have a 32-bit system to cross-grade (want to use the subscription entitlement on a different machine).