I use RHEL 3, but don't want to pay for services I am not using anymore. I want to get away from RH but without doing a full re-install. Can I change to Centos 3 or 4 without too much problems? How do I go about that? I have seen migration schemes for other distro's to Centos but not the most obvious, namely the RH -> Centos, which I want to do.

Thanks for any pointers.

this is *exactly* what i did with a test machine last week... and yes, it was very easy. I bounced via centos 3 to centos 4. what i did have to do was force a database only uninstall of the 2.4 kernel or udev wouldn;t install, that was it though....

here's the thread i used actually - http://www.centos.org/modules/newbb/...d=654&forum=27

and looking at that, when i did go from centos 3 to 4, the new version of yum screwed up my pythonlocations until i was done, so the PYTHON_PATH fix in that thread was also useful for me.

note that as centos 3 is virtually rhel 3 anyway, you should have NO issues whatsoever on that part.

Hi Chris,

Thanks for the pointers! Sorry to ask for more. I don't have a test machine and I need to be sure what I am doing. I have been using linux for a while now but am not very comfortable (yet) when it comes to migrating kernels and distro's. The thread you indicated shows how to upgrade from Centos 3 to 4 and that is pretty self-containing. However you indicated that you needed to 'database-only uninstall of the kernel or udev wouldn't install'. What does this mean, and how do I do it? Then after doing that, how do I actually migrate to Centos, do I follow the pointers at http://www.centos.org/modules/newbb...54&forum=27 ? But that is for going from Centos 3 to 4, right?

Sorry for my confusion. Would really appreciate if you could help me out some more. Thanks!

as i said, rhel3 IS centos3. if you install the centos version of yum and run "yum update" then there will be not much going on. you'll lose the nice redhat images, and get Centos crude attempts instead. you'll go up to centos 3.6, so it depends totally on what updates you've already applied to rhel as to how much is done. IF you have update 6 already, then the change from rhel3 to centos3 will be literally 2 to 3 minutes...

as for the kernel change to centos 4... what i did really is in that thread, post #14 details the steps to trick the system into installing the new kernel.

Hi Chris,

I've installed yum from centos. Then when I run 'yum update' it gives

Gathering header information file(s) from server(s)
Server: CentOS-3 - Addons
Server: CentOS-3 - Base
Server: CentOS-3 - Extras
Server: CentOS-3 - Updates
Error - /var/cache/yum/update/header.info cannot be found
Please ask your sysadmin to update the headers on this system.

How do I update the headers. I've never used yum before (only up2date) so I suppose there are no headers yet. How do I by-pass this?

Thanks again!

Chris, please ignore my last question. For reasons completely unknown to me the 'yum update' command now works after I replaced

http://mirror.centos.org/centos/3/os...s.7.noarch.rpm

with

http://mirror.centos.org/centos/3.4/...s.7.noarch.rpm

This was suggested (although it doesn't say why) in the comments on the thread in

http://www.centos.org/modules/smartfaq/faq.php?faqid=19

Just tried it and it worked. My computer is now updating to Centos. Great thanks! Btw, I gather I shouldn't use up2date anymore right? Should I simply uninstall it (just to make sure I am not touching it anymore)? Or can they (yum and up2date) work together without much problem?

Tim

no no, centos has changed up2date to suit their repo's too. up2date is nothing clever really, uses the same servers as aspt-get or yum, just has a different take in terms of how it should be used

So is there any preference? I see little use in using the two of them, so which is better? I mean, these programs are not complementary are they?

Chris, btw forgot to mention, the update was successful and I am running Centos now! Beautiful! Thanks for all your help, I am really happy with this, especially since there was no need to fully re-install the computer just to get away from RHEL!

I use up2date so that I can be notified when there are updates, but prefer updating using yum.