Today's Vms learn from mainframes

摘要

Few people are more aware of the long history of virtualization than Jim Rymarczyk, who joined IBM as a programmer in the 1960s just as the mainframe giant was inventing the technology that today is reshaping the IT industryrnRymarczyk, still at Big Blue today as an IBM fellow and chief virtualization technologist, recalls using CP-67 software, one of IBM's first attempts at virtualizing mainframe operating systems. CP-67 and its follow-ups launched the virtualization market, giving customers the ability to greatly increase hardware utilization by running many applications at once. The partitioning concepts IBM developed for the mainframe served as inspiration for VMware, which brought virtualization to x86 servers in 1999.rn"Back in the mid-60s, everyone was using key punches and submitting batch jobs," Rymarczyk says."It was very inefficient and machines were quite expensive."rnThe problem of implementing a time-sharing system that would let multiple users access the same computer simultaneously was not an easy one to solve. Most engineers were taking traditional batch operating systems and making them more interactive to let multiple users come into the system, but the operating system itself became extremely complex, Rymarczykrnexplains. IBM's engineering team in Cambridge, Mass., came up with a novel approach that gave each user a virtual machine (VM), with an operating system that doesn't have to be complex because it only has to support one user, he says.