upgrading to fedora core 2

[STYMA, ROBERT E (ROBERT)]

>>Rodolfo J. Paiz wrote:
>> At 09:03 1/22/2004, you wrote:
>> 
>>> In practice, there are some [issues with upgrading from RHL to Fedora 
>>> via apt/yum]:
>>>
>>> http://www.redhat.com/archives/fedora-list/2004-January/msg02421.html
>> 
>> The original question was about upgrading from FC1 to FC2 via apt/yum. I 
>> think the original answer of "in theory, no problem" may or may not be 
>> right but is reasonable. The fact that X or Y problem existed upgrading 
>> from a previous (not even the latest) version of RHL is not relevant to 
>> that question, nor does it imply that the same problems will continue to 
>> exist.
>
>Yes, that is true. And in fact I get the impression few people have had 
>trouble with "yum upgrade"s so far. But I merely report the fact some 
>people have pointed out that problems are theoretically possible.
>
>The article I quoted doesn't refer to problems with a previous upgrade, 
>it discusses the issues that *are* likely to arise in the future. 
>Specifically, if there is a major update of Python or glibc or anything 
>else that yum (or up2date or apt) depends upon that causes it to break 
>during the upgrade process, you're up the proverbial creek (at least 
>until you pop in the CD and fire up anaconda).
>
>It might not happen; it appears not to have happened for 8 -> 9 or
>9 -> FC1. But it *could* happen in the future, and AFAIK the developers 
>haven't designed a system to specifically prevent it. (Please correct
>me if I'm wrong!)
>
>-- 
>       Matt

This sort of problem can happen any time pieces of the tool doing the updating
might get updated.  A decision would have to be made by the person maintaining
yum (or up2date or apt) to link that program together statically.  This way you
would be either running the new copy or the old copy of the updater, but never
pieces of both.  On many UNIX flavors /sbin/sh is set up this way, so that root
can get in even if the system is pretty trashed.