[CentOS] CentOS 6 updating policy

Fri Nov 4 13:57:54 UTC 2011
Ljubomir Ljubojevic <office at plnet.rs>

Vreme: 11/04/2011 02:24 PM, David McGiven piše:
> I am migrating from debian to RHEL (CentOS) and I am wondering how the
> CentOS 6 updating system works.


In first part I will explain normal process, without CR repository 
(which changes things).

> Suppose I install CentOS 6.1 now. Suppose in 8 months CentOS 6.2 is
> released.

Yum update is continuous process. So far (or at present) only way is 
that you will be upgraded to latest minor point-release (.1, .2,...).

> Now I issue a yum update, so my system will be updated to CentOS 6.2, or I
> will have an updated 6.1 ?

In your example, you would have 6.2 when yum update is finished. 
Sometimes "yum upgrade" is recommended, but only if you are advised in 
Release Notes for given point release.

> What if I have been issuing yum update very day just to be sure there are
> no packages with urgent security bugs ? I am having a very updated 6.1 or
> an almost 6.2 ? Or are they the same thing ? I think that during this time
> I should be using Continous Release repository, right ?

There are normal updates against every point release, like updates 
against 6.0 until 6.1 is released, then updates until 6.2, etc. So just 
"very updated 6.1" in your example.

Point releases are mostly used to bring new kernel/hardware support 
(drivers), new versions of core packages (rarely), or new technologies. 
Updates between point releases will only (in most cases) contain bugfixes.

> Also, which is the policy regarding new versions of software, kernel and
> libs ? The bugfixes will be backported or there will be major differences
> between, let’s say, 6.1 and 6.4 ?

Upstream changes (mostly) versions of packages only if there is 
compelling reason to do so. Whole point is to have unchanged system that 
will behave the same as previous point releases. Of course, there are 
deviations from this policy, but as small and as rare as possible.

So short answer is backported bugfixes (even in kernel) and as small 
changes as possible, unless gains are overwhelming and do not brake 


Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe

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