Thank you for the useful advice. One more question will help: does the new kernel support ath5k out of the box on an install?
Perhaps I can just edit the existing /etc/fstab, using device names. The device numbering is inconsistent between GNU/Linux distros under the (what I presume to be) new scheme, with all devices names as /dev/sdX . I'll prepare for a new gentoo install, and hope that the current sabayon continues to act sanely as gentoo, as I update the system, package by package. So far a fair amount of hand work is involved, in updating gnome, for example. Alan