I have a virtual machine running RHEL4 on our cluster server. But IT does not support it anymore. So, I tried to update it to CentOS to enjoy update.
The problem is I have no physical access to the VM, so need to update online.
Neither Redhat nor CentOS suggest to do online update between major releases, but no choice. I did in 2 steps:
- migrate from RHEL4 to CentOS4
- update from CentOS4 to CentOS5
Step1 works like charm, but the 2nd step is nightmare. I followed this article: http://planet.admon.org/howto/update-centos-4-to-centos-5-remotely/ because it is the longest one I found. I guess it is more comprehensive.
- package-cleanup –leaves (then manually yum remove the packages)
- package-cleanup –cleandupes
- yum upgrade (run several times with removing of conflict reported)