I installed RHL7.0 via NFS on a recent PC with a large disk.  I placed the
LINUX / partition above 8.5G (above cyl 1024).  The installation appeared
to be done properly.  When the installer invited me to hit return to
reboot, the X screen disappeared to briefly reveal a scary error message on
the text console.  The message was quickly cleared by the rebooting
process.

The reboot failed.  To cut a long story short, the flashed messages were
from LILO, saying:
  Warning: device 0x0307 exceeds 1024 cylinder limit
  Fatal: sector 26948994 too large for linear mode (try 'lba32' instead)
LILO had therefore not installed a boot sector.
The installer should definitely have reported this problem to me.  It
should have provision to rectify it.  It is lucky that I created a boot
floppy.
The man pages for lilo and lilo.conf make no mention of lba32.  I found
that replacing "linear" with "lba32" in /etc/lilo.con fixed the problem.