[CentOS] Upgrading to CentOS 7

[Stephen Harris]

On Tue, May 19, 2015 at 09:25:30AM -0500, Jim Perrin wrote:
> If you have a good config management environment set up, rolling out a
> new build to replace older systems is much easier than walking through
> an update on each system. I really recommend people use ansible, chef,
> puppet.. whatever they're comfortable with to do some basic automation.

Just do lots of testing, first :-)  There are sufficient differences
between major OS releases (5, 6, 7) that you may need different rules
for each type.

For example, postfix is different version on each so main.cf and master.cf
are different and have version specific differences.
Apache is sufficiently the same between 5 and 6, but 7 has a totally
new way of doing things
And, of course, sysvinit vs upstart vs systemd!

Config managementis a great way of rebuilding a new copy of an existing
version, but it's not a panacea when changing versions.

-- 

rgds
Stephen