Hang on: Isn't that a bit like retrofitting a Toyota Corolla with bulletproof glass and a spare gas tank... just in case?
Not according to PolyServe, which claims the move will boost the overall reliability of its software, thereby knocking down one of the main objections prospective customers have had to deploying it. PolyServe's Matrix Server allows up to 16 servers to share a single file system image. With the multipath I/O feature, the cluster will continue to function even if a switch, storage cable, or host bus adapter (HBA) in a SAN fails (although fully taking advantage of this requires installing two HBAs in each server).
Steve Norall, general manager of Linux Solutions for PolyServe, says multipath I/O has been a key requirement ever since the company first started shipping its product a year ago (see PolyServe's Double Threat).
"It's absolutely something that, early on, customers were continually beating on us for," he says. "They said, 'To move this to a production environment, I absolutely need to have multipath I/O.' If you're going to bet your business on a cluster, they want a completely fault-tolerant SAN fabric."