So I'm lazy. Or stupid. Or both. I did try to follow the instructions
previously pointed at for how to configure RAIDframe with grub and
xen but I messed it up somehow. And on another box I installed
RAIDframe (w/o grub or xen) only to have it run fine, but always come
up with dirty parity after a reboot. Haven't figured out why yet
(suggestions?). So I'm clearly not up to speed on RAIDframe yet.
Check that you have swapoff=YES. Dirty parity on reboot is often a
sign of swap holding the raid set open.