[CentOS] RHEL-6 vs. CentOS-5.5 (was: Static assignment of SCSI device names?)

Sun Jan 30 19:37:19 UTC 2011
Chuck Munro <chuckm at seafoam.net>

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.