COMP9242 Final Exam

Most traditional (monolithic) kernels run device drivers in kernel space. As such, if—for example—a device driver crashes or misbehaves, it is possible for it to bring the entire system down, as there is no isolation between components. VirtuOS separates out whole “vertical slices ” of OS services (eg storage or net-work services, compared to say, isolation between the user, the block device driver and underyling device driver) to run in virtualised environments (service domains). The authors make three main claims regarding the novelness of their paper: • virtualization into service domains, (each directly handling specific system calls) • “exception-less ” system calls between service domains • and that this provides resilience needed of service domains The authors have implemented a prototype atop of Linux and Xen, which they discuss and provide performance results for. They also demonstrate the ability for their implementation to handle termination and restarts of these service domains in case of a failure, and attempt to show the performance benefits that their “exception-less ” system provides