Sistina, a Minneapolis start-up that sells software to let computers store files across a host of computers instead of on a single machine, has named Joaquin Ruiz vice president of marketing and product development, the company said Tuesday. Ruiz previously worked for storage networking start-up Nishan Systems, where he was an early employee and director of product marketing. Ruiz is replacing David Sass, who left Sistina several months ago. Sistina also announced last week that its file system works with Oracle's 9i RAC database software, which uses several smaller servers instead of one larger one and therefore benefits from a file system such as Sistina's GFS. GFS competes with products from Veritas Software, IBM and others.