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

2. 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 !

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

4. 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

5. 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

6. 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

7. 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

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

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

10. 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

11. 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 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

12. 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

13. 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

14. 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

15. Thanks!