Thesis Defense

Agentless Cloud-wide Monitoring of Virtual Disk State

Thesis Document

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Thesis Proposal


This dissertation proposes a fundamentally different way of monitoring virtual disk state in the cloud. The proposed platform is both agentless—meaning it operates external to and independent of the virtual servers it monitors—and scalable—meaning it is designed to efficiently address collections of virtual servers numbering in the thousands. The core technology used to create this platform is called Distributed Streaming Virtual Machine Introspection (DS-VMI), and it leverages two properties of modern clouds: virtualized servers managed by Virtual Machine Monitors (VMMs) enabling efficient introspection, and file-level duplication of data within cloud instances.

We explore a new class of agentless monitoring applications via three interfaces with two different consistency models: cloud-inotify (strong consistency), /cloud (eventual consistency), and /cloud-history (strong consistency). cloud-inotify is a publish-subscribe interface to cloud-wide file-level updates and it supports event-based monitoring applications. /cloud is designed to support batch-based and legacy monitoring applications by providing a file system interface to cloud-wide file-level state. /cloud-history is designed to support efficient search and management of historic virtual disk state. Achieving distributed near-real-time file-level deduplication, key for scalability, leads to a novel application of an incremental hashing construction. We also describe a novel snapshotting method combining the properties of both black box and white box methods which creates near-real-time file-level deduplicated snapshots of virtual disks.

Author: Wolfgang Richter <>

Committee: Mahadev Satyanarayanan (Chair), Gregory R. Ganger, David G. Andersen, Vasanth Bala (Google), Canturk Isci (IBM Research)