[NCLUG] Fedora Core Stuff

[John L. Bass]

David Braley <davbraley at comcast.net> writes:
> How nicely does Fedora play when upgrading between major releases like
> from 4 to 5, or from 5 to 6? Is a fresh install the best way to go? I am
> assuming a "yum update, yum upgrade" keeps you at the same major release
> number like 5.xx or 6.xx.

I have several machines that have been upgraded from RH7 thru FC5/6 without
a clean install. This was done in several ways, depending on the machine:

	1) upgrade process from CD install

	2) upgrade process from net/nfs/ftp install

	3) in place on running system as apt/yum upgrades.

The first two have always been nearly flawless, with some minor exceptions
of some server process configuration files needed manual intervention.

I've used the third on a number of production machines to effect a zero downtime
upgrade, which has been sucessful enough that I've done it on a few dozen machines.
Helps to first take a clone thru the process in the lab to work out the kinks. It's
possible to create a non-functional system this way, so it's wise to have a clone
spare handy should something break. These machines got rebooted once at kernel
switch from 2.4 to 2.6, and a few other times for physical maint ... replacing
power supply fans and disk drives, dust/lint removal -- uptimes of a year or two.
Total service downtime over 5 years of less than an hour.

With apt it was a bit painful, as there were some serious sequencing issues to handle
dependencies that were not well specified in the packages. Mostly required pointing
to the new apt repository, doing a manual upgrade for a few key packages, then doing
it as a large block for the rest of the system. Then picking thru some manual upgrades
mostly deleting obsoletes, and installing some new/replacement packages by hand.

With yum it's a bit cleaner. Need to manually install the release package, then
yum upgrade. There have been a few kinks from FC1 thru FC6, but relatively minor.
It's useful to compare the installed package list of the inplace upgraded machine
with a fresh install machine, and manually delete/install/upgrade a few packages.

Have fun!
John