Virtual Disk based Centralized Management for Enterprise Networks Joint work: Yuezhi Zhou, Yaoxue Zhang, Tsinghua University, China Yinglian Xie, Carnegie Mellon University

Challenge of Enterprise Systems Management of enterprise network systems based on PCs is still a big challenge: PC: Full function desktop computer with native software and data Software maintenance Security Become more complicated with diverse types of OSes and applications coexisting !

Educational Classrooms 1 Every machine has to be installed with OSes and applications 2 System states must be cleaned for each next class

Military Environments Failed!!! Failed!!! 1 Devices can access software and data only in a limited physical area 2 No software or data can be carried outside the network boundary

Existing Management Tools Automatically pushing installation images and patches Examples: Marimba, Ghost Difficult to maintain consistency across machines Vulnerable to errors or attacks due to the existence of local data Out of centralized control Failed

Why Centralized Management Distributed diskless thick clients, yet centralized repositories of all software and data Reduced software maintenance time Enhanced security Availability Heterogeneous OS and application support Easy software migration Easy data backup and recovery

Why Not Thin Clients Performance Cost Poor scalability due to centralized computing Not appropriate for CPU/memory intensive applications Cost Need powerful server Can not leverage the cheap and powerful computing resources of clients

TransCom System Overview Client: bare-hardware like computing platform Sever: Regular desktop computers Connected by Ethernet One such server can support 30-50 clients

Virtual Disk Concept Simulate traditional disks, with disk images holding the actual contents on the server Support heterogeneous OSes and applications transparently

Boot, Sharing, and Isolation Remote OS boot Launch BIOS-enabled Vdisk access function first (replace INT 13H) Load OS, as if with regular hard disks Vdisk sharing, isolation, and recovery Use different types of Vdisk Copy On Write (COW) for system image protection and recovery

Implementation and Deployment Implementation: prototype system supporting Windows & Linux Location: Central South University of Forestry & Technology in China Usage: e-learning classroom for online English Duration time: from May 2005 to July 2006 Numbers of clients: 30 Before After Maintenance time 4-8 hours per week 30 minutes per week Availability 4-8 hours service down time every Thursday No service interruption Security Virus found, physical theft No virus and worms found, no physical theft

Testbed Performance Compared with regular PC One client case is better Ten clients case is comparable Compared with thin-client systems (e.g., Citrix, RDP, and VNC) Application performance (slow-motion, one client) Web browsing: reduce access latency 2-3 times Video playback quality: improve 2-20 times Scalability (i-bench, synchronously) Achieve almost constant latency as opposed to the thin-client systems where latency grows linearly

Related Work Network computers Thin-client systems Proposed by Oracle, Sun, IBM, Apple, etc. Can not support commodity OS and applications Thin-client systems Sun Ray 1 [Sun Micro], RDP [Microsoft], ICA [Citrix] Centralized computing and storage, need high-end servers Networked file systems NFS [Sandberg, 1985] & AFS [Howard, 1988] Can share user data; hard to share heterogeneous OSes Virtual machine based approaches Collective [Chandra, 2005], ISR [Kozuch, 2004] and SoulPad [Caceres, 2005] Can not achieve native performance

Summary and Future Work Centralizing both software and data reduces the management complexity of enterprise networks An example prototype: TransCom Reduce maintenance time and effort Achieve similar performance to PCs Future work Support more types of OSes and devices Optimize performance

Thanks!