I keep multiple copies of everything I've ever written anywhere online with the exception of something like a five- or six- line (or fewer) comment somewhere. That's not only copies of individual originals but copies of different versions of the same thing. It's not only copies in my computer(s) but copies in different locations away from them. It's not only Hubs or other material online. It's also things like answers I've written here on HP's "Answers" section, forum posts that have enough substance to them to make them worth saving (and my bar for "worth saving" is REALLY low), and anything else that I think I may want to use somewhere else (or just have copies of in case I have some need to prove that I wrote something, or that someone else has posted something I wrote).
With regard to Hubs, I do keep track (separate from what's on record on within one's HP profile/account) of published-versus-not-published (etc.) Hubs, as well as copies and records on deleted Hubs.
Of course, keep in mind (even though it doesn't show on my profile under this, my own, name) that I've been writing on HubPages for over nine years now and was writing online (whether for revenue-sharing sites, other sites, or on a "for-hire" type of basis) for a couple of years before that.
These days I have the older account that's drastically cleaned out and in need of further "cleaning" and this one, which I started sometime not long before "Panda", didn't do much with it, and have never really "set roots down in" because "Panda upheaval" has gone on for a big chunk of the time since it first started.
Record-keeping for any Hubs I write on here from now on will be much simpler from here on, but when I started doing anything online I had a number of different reasons for thinking it just made sense to keep copies of everything I wrote (no matter how informal or seemingly insignificant). Aside from the usual "good sense" of keeping copies of one's writing, I'd (a few years before) been sent an "inquiry thing" from an attorney (divorce case') that asked for "copies of all writings" (apparently of any kind). So, with that still "in the air" I was already in a "keep-copies mode" when I started writing online.
No matter how much or how little writing is involved, it takes so little time and space to keep records and copies. It pays to be a little "paranoid" about it when you've put in the care/effort.