[SOLVED] Update to 3.12.9-desktop-1 did not "mkinitrd"

[rickst29]

Resulted in kernel panic upon attempting to load the non-existent initrd (of course). I'm not sure if the cause for failing to build an initrd was:

(a) my use of GRUB2; or
(b) the presence of a previous disk 'sdb', now removed.

And, upon restart with 3.12.8, the MCC "boot configuration tool" was failing to run failed to initialize, it was probably confused by leftover information about the nonexistent 'sdb' device.

If anyone else has the problem - I solved it by first removing references to other devices from /boot/grub/device.map.
Then I used the install DVD to perform an "upgrade" on my already-upgraded system: After licensing and mouse/keyboard selection, the installer finds everything already up-to-date, and goes directly to the post-install configuration menu.

From that menu, I set up (legacy) GRUB as the bootloader.
Next (following system restart using the 3.12.8-2 kernel) I removed the 'grub2' directory from /boot; edited the new stanza into /boot/grub/menu.lst; and ran mkinitrd. Boot of 3.12.9-1 now works.