The Web hosting company The Planet.com Internet Services tests its backup generators monthly and some employees ask if that's really necessary, said manager Urvish Vashi. The blackout in San Francisco Tuesday explains why. Among the 40,000 customers affected by a nearly two-hour electrical blackout in San Francisco was 365 Main, a Web hosting company whose clients include Sun.com, Yelp.com, and Craigslist.com. Their Web sites were among several that were unavailable Tuesday when the local electric utility, Pacific Gas & Electric (PG&E) suffered an outage that cut power to the southern part of the city, including the South of Market area, or SOMA, which is home to several technology companies. The outage served as a reminder of the importance of backup power systems to keep Web sites, and the businesses behind them, running.
