I have Oracle linux 5.8 x86_64 installed on a disk. I tried to upgrade it using the 5.9 DVD. I have done this before (and also for similar RHEL derivatives Centos or Scientific Linux).
Unfortunately it soon bails out with this:
Error mounting device UUID xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx as /boot: No such file or directory.
This most likely means this partition has not been formatted.
But this disk boots. It was installed with a seperate boot partion.
boot is sda1, root is sda2 and home sda5
LVM was not used.