I actually did a no CD/DVD/Floppy/USB stick upgrade. Mounted the DVD image as previously discussed, then copied over the boot image to /boot and edited my grub.conf file to point to that image. (In addition to the normal one.) I was having trouble getting my old instance detected and ended up trying three differeny boot images. I think they all were usable in the end, as the problem seemed to be related to which partition of a mirror I said the DVD iso was on. The install went much slower than when I installed from the DVD (on another faster, but not 7 times faster machine). I think this is because I was updateing the disk that was supplying the update data. If I had been thinking more clearly when I did that, I would have stuck the iso on the unmirrored drive I was using for /tmp and things would have probably gone a lot faster. I wanted to practice this on a machine I have easy access to, since I will be doing something similar to a machine that I don't have easy access to and for which the CD drive isn't normally powered because of a power supply limitation.