Fedora21/22 grub doesn't recognize my raid1/LVM partitions

[John Wright]

I have 2 500G hard drives partitioned with a few 'normal' partitions
for /boot, swap, etc but mostly in a raid 1 array, which is divided
into several LVM partitions.  For many Fedora releases, I have done
fresh installs, preserving the /home LVM partition, and rotating the
root partition among several 30-40G LVM partitions for /. This has
always worked splendidly until Fedora 21/22.  Recently I decided that
it was time to move up to Fedora 22, and with failing that, to
Fedora 21. I have tried several Fedora 22 and Fedora 21.
live install disks (desktop, server) and the server isos.  With the
live disks, the installer doesn't see my existing LVM partitions,
so I can't try to install into them.  With the 21 and 22 server
isos, the installer sees the LVM partitions and appears to proceed
normally, but the final reboot boots into a grub rescue shell, and
the only partition visible to this shell is my /boot partition. I
also tried the Fedora 22 netinstall iso, which also ultimately
resulted in reboot into the grub rescue shell.

I have googled several variations of 'grub doesn't recognize LVM
partitions' without turning up anything helpful.

Have there been changes to the LVM software that might result in
an incompatibility between grub and older LVM versions?

Best,

 	-jmw-