[Centos] Upgrade install using CentOS-3.1 ISO images

Tue Apr 6 18:05:21 UTC 2004
Bart Schaefer <schaefer+centos at zanshin.com>

[This message was held for moderation because the mailing list software
doesn't recognize <schaefer at ...> and <schaefer+centos at ...> as equivalent.
That was last Friday, but still no sign of the moderator dealing with it,
so I'm resending.]

Cutting straight to the chase:

When, if ever, does the installer offer an option to upgrade an existing
installation, rather than wanting to reformat the disks?

More details than you may want:

I recently acquired a new PC chassis, with no operating system but with a
Serial-ATA disk (which I was not expecting when I ordered it).  I set the
BIOS for legacy IDE mode and installed RedHat 9, then attempted to upgrade
the kernel to add SATA support, without much luck.

Searching for the SATA driver modules I found CentOS and decided to try
it.  I downloaded the three ISO images to another PC, burned CDs, and set
about to upgrade my RH9.  However, the installer never offered me the
option of upgrading (keeping my existing filesystems) -- no matter what
steps I tried using when starting the installer, by the time it got to the
page for disk partitioning it always wanted to start from scratch and blow
the existing partitions away.

I finally concluded that I hadn't put anything important on the disks
during my struggle with RH9, so I went ahead with the clean install.  
Everything is working nicely at this point, so thanks for that.

However, there are some other RH9 systems around the office that may need
to be upgraded at some point, and they definitely can't be wiped clean in
the process.  Is there a way to upgrade from RH9 to CentOS?

Any remarks about upgrading from even older RedHat releases?