Hello list members,
My adventure into udev rules has taken an interesting turn. I did discover a stupid error in the way I was attempting to assign static disk device names on CentOS-5.5, so that's out of the way.
But in the process of exploring, I installed a trial copy of RHEL-6 on the new machine to see if anything had changed (since I intend this box to run CentOS-6 anyway).
Lots of differences, and it's obvious that RedHat does things a bit differently here and there. My focus has been on figuring out how best to solve my udev challenge, and I found that tools like 'scsi_id' and udev admin/test commands have changed. The udev rules themselves seem to be the same.
Regarding networking, all of my 'ifcfg-*' files from CentOS-5.5 worked well, including bridging for KVM. Of course, one of the first things I did was remove that atrocious NetworkManager package ... it needs to be rewritten to make it a *lot* more intuitive. RedHat uses it during installation to manually configure the NICs, which I think is a mistake. I much prefer the way CentOS anaconda has done it so far, as a separate install menu form.
The performance of the machine seemed to be better with the newer kernel, which is encouraging. I suspect we can look forward to a number of improvements. I've just managed to scratch the surface. I do expect there may be a few challenges for those of us upgrading a system from 5.x to 6, where some user-written admin scripts could break depending on the system commands they use.
I look forward to CentOS-6 and all the goodies we can expect, and I'm quite happy to wait until the CentOS crew does their thing before releasing it ... they deserve a lot of credit for doing a thorough job all these years.
Chuck