[PLUG] CentOS 6.x to CentOS 7.x

[Keith Lofstrom]

On Thu, Mar 16, 2017 at 06:09:21PM -0700, Thomas Groman wrote:
> ... just start a new CentOS 7 box and migrate your stuff over.

Agreed.  Machines are cheap, especially used (motherboard from
Free Geek?), and bringing up a new distro on the new machine
while leaving the old one running is slightly less painful.
Get a KVM switch and use both.

I use Scientific Linux, a clone of RHEL like CentOS, with
many scientific, engineering, and math packages added.
The SL online community is not nearly as big as CentOS,
and I rely on the CentOS community and FAQs as well, but 
the SL folks solve the same kinds of computing problems
that I do, calculation rather than web-service oriented.

The transition from RHEL6 to RHEL7 (the upstream version that
CentOS and Scientific Linux are copied from) is especially
jarring, much more fraught than RHEL5 to RHEL6 was.  I am
going through the process now because my mind is aging. 
I must upgrade eventually, when RHEL6 reaches end-of-life 
perhaps 6 years from now.

The init change is more painful if you wrote your own init
scripts (I haven't).  A more painful change for me is the
change of firewall control to a GUI.  I am setting the new
SL7 machines up with the older iptables instead, because
90% of my work is through xterm.

The most painful change is gnome3, which is an abomination
unto Cthulu.  Mate is functionally only 90% of gnome 2, but
getting better, while gnome3 is 30% of gnome 2 and getting
worse, more like a video game than a work environment.  
Setting up Mate can be a pain in the ass, but there are
many in the CentOS community helping to make that easier.

Keith

-- 
Keith Lofstrom          keithl at keithl.com