They are all Professors.
In my alta mater, we had a few lecturers (whom we addressed by “Dr” if they held a PhD) in our department, and one professor in the school of engineering.
I suspect it’s a UK-US cultural thing.
When I tried to visit HKU’s website to find out how they do it, all I got was this message. I thought a SAN is supposed to solve the problem of component failure. It doesn’t seem to be the case, althou granted the Wikipedia entry mentions no redundancy.