(Not sure if I should've put this in the Roamio section, but this could involve any TiVo, not just Roamios.) I just set up a Roamio w/external storage, which proceeded along Guided Setup swimmingly until the System Update notice. Upon one of the (repeated) restarts (not sure which one), I got the dreaded GSD (which even to this day fills me with deep depression). A GSD-restart cycle began, and what little kept my heart from sinking completely was the irregular length of the intervals, implying something more than vain robotic repetition might be at play. Sure enough, one restart resulted in not being able to detect the external storage. Unplugging, turning the external on/off, and replugging the TiVo resulted in another round of GSD restarts. One detail I failed to mention yet: the "in-use" light(s) on the external storage drive was flashing furiously throughout this dance. Finally--amazingly, miraculously--the TiVo proceeded to an installation of the System Update, and then to the initialization music video. I finally exhaled. Anyone out there have any idea what happened? And how it got fixed? Up until now, my experience with GSD involved infinite restart loops resulting in a TiVo brick. The eventual resolution was a shocker, and forgive my pessimism if I'm not yet entirely sure that this unit is stable.