Joint work:

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
• 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 30-50 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 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
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
• 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!