Updating Linux

[senthil_kumar_1]

Hi All,

I have some doubts about updating Linux OS...

1)Can we update Linux OS (rhel and suse) from one version to another version?

2)How to update RHEL 4.0 to RHEL 5.0?

[Matti_Kurkela]

1.) It depends on the particular Linux distribution and version. In most cases, the "Installation Guide" or similar document has "how to update from the previous version to this one" instructions, if update is possible.

2.) Please see RHEL 5 Installation Guide. as it has an entire chapter on upgrading:

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Installation_Guide/ch-upgrade-x86.html

Quote:

Red Hat does not support upgrades from earlier major versions
Although anaconda provides an option for upgrading from earlier major versions of Red Hat Enterprise Linux to Red Hat Enterprise Linux 5.6, Red Hat does not currently support this. More generally, Red Hat does not support in-place upgrades between any major versions of Red Hat Enterprise Linux. (A major version is denoted by a whole number version change. For example, Red Hat Enterprise Linux 4 and Red Hat Enterprise Linux 5 are both major versions of Red Hat Enterprise Linux.)
In-place upgrades across major releases do not preserve all system settings, services or custom configurations. Consequently, Red Hat strongly recommends fresh installations when upgrading from one major version to another.

While upgrading from Red Hat Enterprise Linux version 4 Update 4 is technically possible, you are more likely to have a consistent experience by backing up your data and then installing this release of Red Hat Enterprise Linux 5.6 over your previous Red Hat Enterprise Linux installation.

To upgrade from Red Hat Enterprise Linux 4 you should bring your system up to date using RHN before performing the upgrade.

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

i.e. if you have RHEL 4 Update 4 or later, it is technically possible to update... but RedHat recommends a complete reinstallation of the new version instead.

[Nighwish]

Hello

You can upgrade Linux using the CD or a ISO image.

Do a backup of your important data before you do such task.

Also read the upgrade section of manual to your corresponding distribution.

Regards.