thanks for letting us know how things turned out!
> I tracked down the problem to a vsftpd package I installed in July. It in turn installed systemd and a number of other packages which altered how the OS booted.
This then was no SLES RPM (but rather sounds like an opensuse RPM, as that distribution has already switched to systemd). I *strongly* recommend to only install what is required on a server and known to you, and as can be seen in this case, unknown packages can cause a lot of harm (although the "unknown package" itself need not be harmful nor malicious - it may simply be, as in your case, unsuitable for the target system).
Just for the records (and others stumbling across this thread), there's a SLES-supported vsftpd package included in the SLES distributions. I assume that for whatever reason, you were looking for a different (probably newer) version of that software, and came across some RPM not intended for your version of SLES.
Reinstalling the OS may well have been the best choice and I'm glad to read you're back on track.