I recently built a CentOS 6 system as my main machine at home. With a bit of help from members of this list, it is now working better than the machine it replaced (RIP). The new machine works so well, that I would like to convert some CentOS 5 machines to CentOS6.
I did some research on the web and the new install is still considered the proper way to upgrade CentOS. Same as Fedora and RHEL. The question becomes, "What makes the Ubuntu developers so clever that they can do major upgrades through their apt based update system?"
There must be some sort of gotcha or tradeoff involved in allowing this.
Does anyone have any insights on why they can get away with this while CentOS cannot?
To add to Les' points, Fedora has offered in place upgrade, going at least as far back as FC1 -> FC2. I seem to recall that I used to be able to upgrade my free RHL (non-enterprise) versions in place, as well, but I won't swear to it.
On 02/25/2014 06:06 PM, Mike Burger wrote:
To add to Les' points, Fedora has offered in place upgrade, going at least as far back as FC1 -> FC2. I seem to recall that I used to be able to upgrade my free RHL (non-enterprise) versions in place, as well, but I won't swear to it.
the actual delta between released code has a lot to do with it - if the delta is small, then its an easier in place upgrade.
secondly, since the verisons dont come from the same universe of packages and repos, there is some work to be done - manually - to handle orphans, obsoletes and functional changes.
thirdly, it is actually possible to go from c5 to c6 without an upgrade, but working through the process to handle corner cases and the orphans / functional changes means there are multiple reboots involved.
All said and done, automate and script the setup process as much as possible - so you only ever need to do it once. And use macros to define and work with exception and changes in versions of code, so you can dual maintain multiple versinos from the same scripts.
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Karanbir Singh -
Mike Burger