Hi,
Starting with http://wiki.centos.org/FAQ/CentOS3 I wanted to test how to migrate my x86_64 machine from in installed RHEL5 (fully updated) to the current CentOS5 without reinstalling.
The steps I had to do were:
1. steps in RHEL5: a. yum clean all b. installing RPM-GPG-KEY-CentOS-5.htm from http://mirror.centos.org/centos/ (by rpm) c. installing by rpm from http://mirror.centos.org/centos/5/os/x86_64/CentOS/ the rpm's
centos-release centos-release-notes redhat-logos yum
partially I had to use the --force option for rpm.
d. Trying yum upgrade. This step failed with the error msg: ---------------------------------------------------------------------------- Error Message: Your account does not have access to any channels matching (release='5', arch='x86_64-redhat-linux') If you have a registration number, please register with it first at http://www.redhat.com/apps/activate/ and then try again. Error Class Code: 19 Error Class Info: Architecture and OS version combination is not supported. Explanation: An error has occurred while processing your request. If this problem persists please enter a bug report at bugzilla.redhat.com. If you choose to submit the bug report, please be sure to include details of what you were trying to do when this error occurred and details on how to reproduce this problem. -----------------------------------------------------------------------------
I found out that files in /etc/sysconfig/rhn were responsible for this behaviour, so i uninstalled rhn-client-tools (from RHEL5) using the --justdb option and moving /etc/sysconfig/rhn to /etc/sysconfig/rhn.bak.
Because /etc/sysconfig/rhn belongs to the centos-release package too, I made a re-install of this package.
e. Now I could run yum upgrade which upgraded my system to CentOS-5 without any error msg. f. reboot into CentOS
2. Steps in CentOS a. the grub entries in /boot/grub/menu.lst were not updated: The title commands had to be changed to Centos, but re-installing the kernel had the same effect. b. Booting into initmode 5 and trying a graphical login failed because of missing themes (/usr/share/gdm/themes/CentOSCubes/CentOSCubes.xml) which belong to the redhat-artwork package. After reinstalling this package all OK.
3. The time I needed for migrating: about 15 Min. I think this time may be reduced if all pitfalls are known _before_ starting the migration.
Any issues?
Regards
Joachim Backes joachim.backes@rhrk.uni-kl.de University of Kaiserslautern,Computer Center [RHRK], Systems and Operations, High Performance Computing, D-67653 Kaiserslautern, PO Box 3049, Germany -------------------------------------------------- Phone: +49-631-205-2438, FAX: +49-631-205-3056 http://hlrwm.rhrk.uni-kl.de/home/staff/backes.html