[Centos] Upgrading from 3.4 to 4.0 beta X

Sat Jan 22 10:13:42 UTC 2005
Johnny Hughes <mailing-lists at hughesjr.com>

On Fri, 2005-01-21 at 23:58 -0800, Michael Taylor wrote:
> Please forgive me if I missed something, but I've searched all over in
> hopes of finding something documented on a procedure to upgrade a
> Centos 3.4 system to the beta.  I've got the DVD burned and am testing
> the process on VMWare.  All I could figure out how to do was install
> over the existing partition without formatting, but this was quasi-
> disastrous so I 'reverted' my VMWare drive to the prior state.  Is
> there some way to reconfigure yum.conf, GPG keys, etc. so that it will
> pull down the changes?  Or, is there a way to 'upgrade' the system
> using the CD as a source?  Any help would be appreciated.  I was
> hoping it was as simple as the upgrade from 3.3 to 3.4, but I couldn't
> find anything out there.

Upgrading via yum is very hard, and the results are not very good ...
there are many things that change to vastly different versions.  I can
almost guarantee you will have some kind of issues after an upgrade with

The best (and most consistent) way to upgrade is to use anaconda, at the
ISO linux bootprompt on the CD use the command:

linux upgradeany

The anaconda routine produces the most consistent upgrades ... BUT, if
you have anything outside the standard CentOS 3.x installed (like DAGs
yum repo stuff), you may have issues.
RedHat discourages upgrades, from the RedHat RHEL 4 beta install manual:

Although upgrades are supported by the Red Hat Enterprise Linux family
on x86 processors, you are more likely to have a consistent experience
by backing up your data and then installing this release of Red Hat
Enterprise Linux 3.93 over your previous Red Hat Enterprise Linux

This recommended reinstallation method helps to ensure the best system
stability possible.

For more information about re-installing your Red Hat Enterprise Linux
system, refer to http://www.redhat.com/docs/wp/ 

If you currently use Red Hat Enterprise Linux 3 on an x86 system, you
can perform a traditional, installation program-based upgrade.

However, before you chose to upgrade your system, there are a few things
you should keep in mind:

      * Individual package configuration files may or may not work after
        performing an upgrade due to changes in various configuration
        file formats or layouts.
      * If you have one of Red Hat's layered products (such as the
        Cluster Suite) installed, it may need to be manually upgraded
        after the Red Hat Enterprise Linux upgrade has been completed.
      * Third party or ISV applications may not work correctly following
        the upgrade.

Upgrading your system installs the modular 2.6.x kernel as well as
updated versions of the packages which are currently installed on your

The upgrade process preserves existing configuration files by renaming
them with an .rpmsave extension (for example, sendmail.cf.rpmsave). The
upgrade process also creates a log of its actions in /root/upgrade.log.

As software evolves, configuration
file formats can change. It is very
important to carefully compare your
original configuration files to the
new files before integrating your

It is always a good idea to back up
any data that you have on your
systems. For example, if you are
upgrading or creating a dual-boot
system, you should back up any data
you wish to keep on your hard drive
(s). Mistakes do happen and can
result in the loss of all of your

Some upgraded packages may require the installation of other packages
for proper operation. If you choose to customize your packages to
upgrade, you may be required to resolve dependency problems. Otherwise,
the upgrade procedure takes care of these dependencies, but it may need
to install additional packages which are not on your system. 

Depending on how you have partitioned your system, the upgrade program
may prompt you to add an additional swap file. If the upgrade program
does not detect a swap file that equals twice your RAM, it asks you if
you would like to add a new swap file. If your system does not have a
lot of RAM (less than 128 MB), it is recommended that you add this swap

If you still choose to perform a traditional upgrade, type the following
command at the installation boot prompt:

linux upgradeany

Johnny Hughes