[CentOS] Upgrade from CentOS 5.x to 6.0

[Ljubomir Ljubojevic]

Trey Dockendorf wrote:
> Great news about CentOS 6.0 being available, and I figured I'd ask the 
> most obvious question, what can I expect when upgrading from CentOS 5.6 
> to 6.0?  I have not had to go from one major version of CentOS to 
> another so this is new territory for me.  Is the processes just like an 
> install except there's an "Upgrade" option?  Does an upgrade do a "yum 
> update" of everything installed?  Most of my systems use EPEL and some 
> the IUS repos...is there a way during the upgrade to just upgrade system 
> components and leave things like PHP, httpd and MySQL alone for now? 
>  Any suggestions on monitoring the upgrade progress via syslog or some 
> other method so I can see exactly what is being done during the upgrade?
> 
> Thanks
> - Trey

Direct upgrade is NOT supported. You are advised to backup your old 
system, save all relevant parameters and personal data and do a clean 
install.

I think CentOS 6.0 by default uses etx4 partitions that are better then 
old ext3, so I would advise total reformat of root partition (*after* 
backup) and fresh install on newly formated partition.

Ljubomir