I am able now to boot to both OSes on the system, manually through GRUB,
thanks to Felix Miata and others. In 11.3, most facilities seem to be
working, except that I am unable to log on to a website using Firefox (I
have so far tried only one such site). In 11.1, everything seems to be in
order, as long as it doesn't involve communication (network, USB sticks).
I have extracted the first section of the <messages> messages log for both
installations; these can be seen at ftp://hashkedim.com/pub. I wanted to
try booting to each of the OSes, through the GRUB on each of the drives. I
think the filenames clarify which file is which; e.g.