Web Hosting Talk : Web Hosting Main Forums : Hosting Security and Technology : Hosting Security and Technology Tutorials : HOW-TO: yum upgrade; redhat 9 -> CentOS 3.1

[Haze]

What is CentOS?: CentOS is essentially a rebuild of the RHEL source code. I've been using this OS for a couple weeks now with no issues running cpanel.
More info on CentOS can be found on the web site:
http://www.centos.org

Here are the steps i took to update a Redhat 9 box running on a minimal install ( no X, etc ) as suitable for a server to CentOS 3.1 ( which is a fork of RedHat Enterprise Linux v3 )..

I took a fresh install of redhat 9, slapped it on a test box then updated it with up2date. I then installed yum for redhat 9 which can be found here:
Yum Download

Now, you might want to rebuild the rpm database, just incase, thats up to you:
# rpm -vv --rebuilddb

I then modified /etc/yum.conf to look like this:

[main]
exclude=httpd* mysql* php* perl*
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=redhat-release
installonlypkgs=kernel kernel-smp kernel-hugemem kernel-enterprise kernel-debug kernel-unsupported kernel-smp-unsupported kernel-hugemem-unsupported
tolerant=1
exactarch=1

[base]
name=CentOS-$releasever - Base
baseurl=http://mirror.pacific.net.au/linux/cAos/centos-3/3.1/os/i386/
gpgcheck=1

#released updates
[update]
name=CentOS-$releasever - Updates
baseurl=http://mirror.pacific.net.au/linux/cAos/centos-3/3.1/updates/i386/
gpgcheck=1

#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
baseurl=http://mirror.pacific.net.au/linux/cAos/centos-3/3.1/addons/i386/
gpgcheck=1

#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirror.pacific.net.au/linux/cAos/centos-3/3.1/extras/i386/
gpgcheck=1

Change "http://mirror.pacific.net.au" to a mirror near you, a list can be found here:
CentOS Mirrors

After that you need to import the GPG key for the centos RPMs. Issue the following command:
# rpm --import http://mirror.centos.org/centos/3.1/i386/RPM-GPG-KEY-CentOS-3

Nows the time you want to check you have made appropriate backups, etc ( i hope you all test this out before rolling production servers! ).

Next step is to run the following command:
# yum upgrade

This will download the rpm headers and determine what needs to be done, play carefull attention of course here and in all parts if this process for errors. Yum will then ask you if you are sure you want to go ahead, if no errors are present, press "y" then "enter".

This process will take a while, depending on your connection and the gear your installing it on of course. Go brew a fresh pot of coffee, order a pizza, grab a movie or GET BACK TO WORK YOU!!!!

After thats done, check for errors, make sure the new kernel is installed by issueing:
# rpm -qa|grep kernel

You should be presented with a kernel versioned like this: 2.4.21-15.EL.c0 as well as your other kernels previously installed. Check your boot loader to make sure the new kernel is default.

Finally run:
# yum update

Just to ensure you have everything you need.

Now your set to reboot ( hopefully ):
shutdown -rf now

This worked like a charm for me, hope you all can make use of this somehow

[AH4YOU]

its little hard to do thast i think

[Haze]

Its fairly straight forward actually, what are you stuck on?

[Steven]

yes looks very stright forword

[Steven]

[root@opium root]# uname -r
2.4.21-15.EL.c0
[root@opium root]# cat /etc/*release*
CentOS release 3.1 (final)
[root@opium root]#


Here's a direct admin box upgraded from rh9

[Haze]

thnx TLG for testing that out.. ur a legend!!

And just incase, cuz i've had a couple people have this issue now, if the EL kernel doesn't install ( rpm -qa | grep kernel <- to check + cat grub.conf ; else lilo.conf ), make sure you download the rpm and rpm -ivh kernelfilename.rpm and modify your boot loader ( be it lilo or grub ) before you reboot! The rpm can be found on any of the CentOS mirrors.

[Steven]

The upgrade seems very stable. On a side note, it does not break anything with directadmin. I did not have to fix anything. I did however have to add a few http related thing to the skiplist and webalizer.

[rtoledo]

Originally posted by thelinuxguy
The upgrade seems very stable. On a side note, it does not break anything with directadmin. I did not have to fix anything. I did however have to add a few http related thing to the skiplist and webalizer.

Man I'm glad I came across this post on google, I wanted the Redhat 3. es and this release does it just as good!

now to play around with Tomcat and Java

[2uantuM]

has anyone tried this on cpanel boxes?

[Haze]

So far i've done 1 personal production redhat 9 cpanel box no problems. That box also had ircd's and eggdrops on it. No reported problems.

I've been in contact with others that have successfully migrated their cpanel rh9 to centos via this howto as well with no issues.

[thaphantom]

A good yum.conf for the USA

[main]
exclude=httpd* mysql* php* perl*
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=redhat-release
installonlypkgs=kernel kernel-smp kernel-hugemem kernel-enterprise kernel-debug kernel-unsupported kernel-smp-unsupported kernel-hugemem-unsupported
tolerant=1
exactarch=1

[base]
name=CentOS-$releasever - Base
baseurl=http://caos.nplus1.net/centos-3/3.1/os/i386/
gpgcheck=1

#released updates
[update]
name=CentOS-$releasever - Updates
baseurl=http://caos.nplus1.net/centos-3/3.1/updates/i386/
gpgcheck=1

#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
baseurl=http://caos.nplus1.net/centos-3/3.1/addons/i386/
gpgcheck=1

#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=http://caos.nplus1.net/centos-3/3.1/extras/i386/
gpgcheck=1

Taken from myCPAdmin.com

[Apoc]

Would this work for Fedora to Centos too?

[Haze]

Simple Answer: No! This how-to will not work with fedora as it is much newer than centos 3.1.

As fedora has newer technologies ( newer gcc, kernel, etc ) this would be a very trickey transition. In essence, you will be *downgrading* the box. I have not had the chance to test this as we only use 1 fedora box that we are migrating clients to a brand new box shortly, thus I have not personally had the need to do so.

Complicated answer: I know it has been done, but just what needs to be done to enable a smooth transition I am unsure of. You may want to contact thelinuxguy on these boards or through his web site: http://www.rack911.com as I am sure he's told me he has done it with success.

[Apoc]

Hm that's too bad. The reason that I wanted to try it is that CentOS is much less of a beta product than Fedora is. The problem here would be that I'd have to upgrade the OS on about 50 machines every time they release a new version..

[Steven]

if i had another test box with me i could make a tutorial probably.