The ability to save and restore the state of running systems can enable a variety of useful features like suspend-to-disk, system checkpointing, system migration, and many others. Unfortunately, restoring a saved system is time-consuming, discouraging the use of save and restore features. Restoring is expensive primarily because fetching…
This paper introduces a novel algorithm for IO resource allocation in a hypervisor. Our algorithm, mClock, supports proportional-share fairness subject to minimum reservations and maximum limits on the IO allocations for VMs. We present the design of mClock and a prototype implementation inside the VMware ESX server hypervisor.…
Shared-memory multiprocessors (SMPs) are being extensively used as general-purpose servers. The tight coupling of multiple processors, memory, and I/O provides enormous computing power in a single system, and enables the efficient sharing of these resources. The operating systems for these machines (UNIX or Windows NT) provide very few…
VMware ESX Server is a thin software layer designed to multiplex hardware resources efficiently among virtual machines running unmodified commodity operating systems. This paper introduces several novel ESX Server mechanisms and policies for managing memory. A ballooning technique reclaims the pages considered least valuable by the operating system…
Commodity operating systems entrusted with securing sensitive data are remarkably large and complex, and consequently, frequently prone to compromise. To address this limitation, we introduce a virtual-machine-based system called Overshadow that protects the privacy and integrity of application data, even in the event of a total OS compromise.…
We use a novel virtualization-based approach for computer architecture performance analysis. We present a case study analyzing a hypothetical hybrid main memory, which consists of a first-level DRAM augmented by a 10-100x slower second-level memory. This architecture is motivated by the recent emergence of lower-cost, higher-density, and lower-power…
For the majority of common workloads, performance in a virtualized environment is close to that in a native environment. Virtualization does create some overheads, however. These come from the virtualization of the CPU, the MMU (Memory Management Unit), and the I/O devices. In some of their recent x86…
