To address the limitations of centralized shared storage for cloud computing, we are building Lithium, a distributed storage system designed specically for virtualization workloads running in large-scale data centers and clouds. Lithium aims to be scalable, highly available, and compatible with commodity hardware and existing application software. The…
Deterministic record-replay has many useful applications, ranging from fault tolerance and forensics to reproducing and diagnosing bugs. When choosing a record-replay solution, the system administrator must choose a priori how comprehensively to record the execution and at what abstraction level to record it. Unfortunately, these choices may not…
Execution trace is an important tool in computer architecture research. Unfortunately, existing trace collection techniques are often slow (due to software tracing overheads) or expensive (due to special tracing hardware requirements). Regardless of the method of collection, detailed trace files are generally large and inconvenient to store and…
VMware ESX Server is a software platform that efficiently multiplexes the hardware resources of a server among virtual machines. This paper studies the performance of a key component of the ESX Server architecture: its storage subsystem. We characterize the performance of native systems and virtual machines using a…
This paper describes the design and implementation of a system that uses virtual machine technology to provide fast, transparent application migration. This is the first system that can migrate unmodified applications on unmodified mainstream Intel x86-based operating system, including Microsoft Windows, Linux, Novell NetWare and others. Neither the…
Deployment of shared storage systems is increasing with rapid adoption of virtualization technologies to provide isolation, better management and high utilization of resources. Quality of service (QoS) in such environments is quite desirable for meeting IO demands of virtual machines. The lack of QoS support at typical storage…
Analyzing the behavior of running programs has a wide variety of compelling applications, from intrusion detection and prevention to bug discovery. Unfortunately, the high runtime overheads imposed by complex analysis techniques makes their deployment impractical in most settings. We present a virtual machine based architecture called Aftersight, which…
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…
Rapid adoption of virtualization technologies has led to increased utilization of physical resources, which are multiplexed among numerous workloads with varying demands and importance. Virtualization has also accelerated the deployment of shared storage systems, which offer many advantages in such environments. Effective resource management for shared storage systems…
Interrupt coalescing is a proven technique for reducing CPU utilization when processing high IO rates in storage and networking controllers. Virtualization introduces a layer of virtual hardware whose interrupt rate can be controlled by the hypervisor. In this paper, we present the design and implementation of a virtual…
