Confusion on SCSI machine after preupgrade

[Timothy Murphy]

After finally getting preupgrade to work on my SCSI machine
(after modifying initrd* according to
<http://fedoraforum.org/forum/showthread.php?p=1125626>)
the machine appears to be confused about the 3 disks on the machine.
The SCSI disks which were sda and sdb have become sdb and sdc
while an IDE disk (used for backup) has become sda.

These changes do not seem to be reflected in /boot/grub/devices.map
which has not changed, seeing sda and hd0 and sdb as hd1.
Sdc is not mentioned.
As far as I can see, this conflicts with the output of blkid .

Everything works fine, presumably because the UUIDs are used.

But all this made me wonder where exactly the disks are named
sda, sdb, etc?

Also, how can I tell on which disk's MBR the bootloader is installed?