Moving from FC 4 to 5
The first problem occur ed when the installer attempted to mount /usr. This is mirrored on two different hard drives and the installer could not recognize it. The most annoying thing about the Fedora installer is that it automatically reboots when ever it runs into trouble.
All that was needed to solve this mount point problem was to edit the fstab file and make the /usr entry point to one of the partitions that make up the RAID array. Unfortunately to do that I had to reboot in rescue mode and then boot again to restart the upgrade. Guess what there is another error. This time it's complaining about my backup folder which is also mirrored.
Why the installer is examinig this mount point is a mystery to me. Why it went undeteced earlier is an even bigger mystery. So I need to reboot again to change the fstab file.
On the third attempt the installer complained about '/usr/tmp/' being a directory and promptly rebooted. This time though instead of going into the rescue console, I switched to the console with ctrl-F2 and made the /usr/tmp into a symbolic link. Installer promptly complained about the link not being a relative link and rebooted once more.
After changing that the, the next complaint was about the boot loader not being recognized. But it should have been cause it's just Grub. After skipping this step, the files were finally copied and it ran onto for 50 minutes. Fortunately I am using a DVD image rather than CD images like the last time.
The troubles didn't end there. Booting the OS failed because mdadm had already started the raid by the time the boot process attempted to mount /usr. The DVD went back into the drive for another boot up in rescue mode, for yet another edit of fstab but finally the system did start up.