In any barroom debate over the most successful restaurant in the Roanoke Valley, Va., it’s a sure bet Mac and Bob’s in Salem would make many of the short lists. Launched in 1980 with 10 stools in a rented cubbyhole on East Main Street, the restaurant now seats 330 and still has occasional lines to get in. It’s not at all a stretch to call it a Salem institution, The Roanoke Times reported. That growth has occurred in an industry in which most independent operators do not last five years. Now, owners Bob Rotanz and Joe Dishaw are in a jam they never anticipated. They gathered scores of employees together and announced the restaurant is filing for chapter 11. Mac and Bob’s will remain open, but how did they get here? It’s a bizarre story that involves servers and dishwashers, shared tips and federal wage-and-hour laws. The saga also includes a Texas lawyer and a lawsuit filed by a server who quit in April. Mac and Bob’s inadvertently violated the law by requiring its servers to share a small portion of their tips with dishwashers, a policy that stretches back at least 20 years. Until recently, Rotanz had no idea that practice was illegal. The dishwashers were already earning at least $9 per hour before those tips. The policy required servers to share 1 percent of their nightly sales with the dishwashers. While it is legal for restaurants to require tip-sharing between servers and other dining-room employees, federal law prohibits sharing tips with kitchen staff unless the restaurant pays servers at least $7.25 per hour, the federal minimum wage.