I do love the technical parts of the discussion here but do allow a slightly different perspective: You say it is for a client and you (presumably) can bill the

I do love the technical parts of the discussion here but do allow a slightly different perspective: You say it is for a client and you (presumably) can bill the client for this extra service. That being the case, aren't you better off using a commercial solution like others mentioned below (CrashPlan/rsync etc) and charge the client for the same? This way you have a level of support and accountability than being liable for everything that can go wrong with the hacks. I would, of course, encourage your quest for a hackable Wireless SSD for your personal projects :-)