best remote upgrade method (rh9->fc2)

[John Reiser]

> can anyone give me some advice for a method to upgrade a remote server from
> rh9 to fc2?
> 
> Also, this is a production server, so some advice on how to this in the 
> safest way would be appreciated.

If safety really matters, then you must be prepared to roll back
to your current configuration with rh9, as well as roll forward
to a new configuration with fc2.  Make a complete backup of
all data first, and TEST IT to be sure that the media are readable
and reliable, and that the restore procedure works!

One very effective way to test the backup can be to restore it
to a completely different physical machine.  If the new machine
works when running the restored backup, then you can do a fresh
install of fc2 on the old machine (preserving "data" partitions),
and keep other machine around for a while for insurance.  If you
own the datacenter, then just borrow the second machine for a week.
If the machine is in a colocation service facility, then rent
a clone of your setup for a month.

If you cannot arrange a separate machine, then you are already
running with safety that is less than ideal.  But you can make do.
The safest way requires having planned ahead for such an upgrade
when rh9 was installed.  Namely, have two separate root partitions:
one for the current system, one for the next system.  In all, you
should have at least 5 partitions: boot (50MB), current root (>=2GB),
next root (>=2GB), swap, everything else.  Install fc2 to the new root,
copy system-specific info (such as the password files) from old to new,
and test the new system.  Then roll forward to fc2 if it works, and
roll back to rh9 if it doesn't.

The first thing you must do is fix a bug in your existing rh9 kernel.
The use of extended attributes by SELinux in fc2 will make your old
rh9 kernel unusable in such a multi-booting situation.  See these two:
      https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=137068
      https://bugzilla.fedora.us/show_bug.cgi?id=2205
If you do not fix this bug in rh9, then you must completely disable
SELinux when you install fc2.

Once you have an rh9 that tolerates extended attributes, and a spare
partition to hold the new fc2, then use what's in /isolinux on fc2.
Boot a copy of /isolinux/vmlinuz and /isolinux/initrd.img using
"askmethod"; then install fc2 over the network via ftp or http.
Or, put copies of the complete fc2 .iso files onto another spare
partition, and use those for a local disk install.

Attempting a direct upgrade install from rh9 to fc2 using the same
root filesystem is an invitation for disaster.  There are cases when
it works, and cases when it does not.  Can you afford to find out
which case applies to your system?  Perhaps you can, if you have
a good, tested, reliable, trusted, complete backup before you start.

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