3.4 is the most widely used version of CentOS in the hosting market, because it is the latest version before SELinux was introduced (which is the cause of many CPanel problems). Some admins have managed to get CPanel working on CentOS4, but Iv'e heard it's quite a task. There was a thread about 4.0+CPanel somewhere, you may want to try searching for it.
And as far as migration, I have heard both the good and bad stories of RH9 > CentOS3x. Many people have had unbootable systems after the upgrade, however others have had outstanding success with absolutely no problems. Just make sure you have a good firm backup of the system before you begin.
3.3 is obsolete any more. In fact, if you're running 3.3 and you do a "yum update", you'll be taken to 3.4 now, depending on the server mirrors you use.
4 is getting there, but it's still not as supported by control panel stuff, just as rhel4 isn't quite supported (though close).
Best answer? 3.4 all the way!
Sorry, didn't see this one:
Could I have any problem migrating from RH9.0 (my actually machine) to CentOS ?
If you know what you're doing, then no, you shouldn't have any problems at all. HOWEVER, if you don't, then you will have them, because there are issues that you will need to resolve before upgrading.
Personally, I've had great success migrating 9.0 (and earlier) to CentOS. Again, if you know what you're doing, you should have no problem at all.
Last edited by whmcsguru; 04-29-2005 at 02:43 PM.
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