On Tue, Jan 10, 2012 at 1:35 PM, m.roth@5-cent.us wrote:
We've got about 200 existing servers running CentOS/RHEL 5.6 and all new servers are being provisioned using CentOS/RHEL 6.1. So that everything is consistent we need to upgrade the servers running CentOS/RHEL 5.6. I've searched the CentOS wiki, the Red Hat site, and the internet looking for something official on upgrading/migrating from CentOS/RHEL 5.x to CentOS/RHEL 6.x. There's got to be a way other than having 2 times hardware.
Any ideas???
What we do is build one, then create /boot/new and /new on the next server, rsync over to them, then mkdir /boot/old and /old, and (using zsh with modules loaded) mv * old, mv old/lost+found ., mv old/new/* ., make sure a few things are correct (for example, ifcfg-eth*, /etc/ssh/), and sync, then reboot. All your other stuff is fine....
Have you looked at http://rear.sourceforge.net/ (and in EPEL) as a potential backup/clone/rollout mechanism? It seems like something that might suit your sensibilities, but I'm not sure what kind of contortions you would need to do to boot into its recovery image remotely. For anyone too lazy to look, it builds a bootable iso containing your own current system's tools to re-install itself, recreating the filesystem (LVM/raid/partitions) and dropping in a backup that can be included or separate. It is intended for mostly automated restores back onto the same system but I think it can be abused for cloning and there is a point where you can adjust the filesystem layout.