chinav: experiences on virtualization technology · • as the technology base of cloud computing,...

®

ChinaV: Experiences on Virtualization Technology

Hai Jin,

Huazhong University of Science and Technology

®Outline

• Introduction of ChinaV Project

• Experiences on Virtualization Technology

• Conclusions

®What is ChinaV

• Research on Fundamental Theory and

Approach of Computing System

Virtualization, supported by National 973

Basic Research Program of China under

grant No.2007CB310900

• Started from 2007 to 2011 with total budget

RMB 26M

http://grid.hust.edu.cn/973http://grid.hust.edu.cn/973

®Visions

• Virtualized Resources Environment

– Combine or divide resources: good granularity and

transparence

• Virtualized Tasks Environment

– Build task executing environment on-demand: high

utilization and efficiency

• Virtualized User Environment

– Desktop virtualization: high convenience, good user

experiences


®Missions

• Theoretical model and architecture of the virtualized computing system

• Single-dimensional system resource virtualization

• Multi-dimensional system resource virtualization

• Pervasive computing environment of virtualized system

• Security and trusted scheme of the virtualized computing system

• Theory and approach of evaluating virtualized computing system

• High performance based virtualization technology

• Application of virtualized simulation system


®

Research Teamhttp://grid.hust.edu.cn/973http://grid.hust.edu.cn/973

®Outline


• Experiences on Virtualization

Technology

– Live Migration

– Power Management

– Memory Virtualization

– Desktop Virtualization

• Conclusions

®Outline



– Live Migration




• Conclusions

®

CR/TR-Motion: A Novel VM Migration Approach

• Revirt is adopted

• Checkpointing/recovery with trace/replay

technology are used to provide fast and

transparent live VM migration

• We orchestrate the running source and target

VM with execution trace logged on the source

host

H. Liu, H. Jin, X. Liao, L. Hu, and C. Yu, “Live Migration of Virtual Machine Based on Full System Trace and Replay”, Proceedings of the 18th International Symposium on High Performance Distributed Computing (HPDC'09), ACM Press, June 11-13, 2009, Munich, Germany, pp.101-110

®CR/TR-Motion System Structure

®CR/TR-Motion: Migration Process

AB

Checkpoint

log2

……

Replay log1

……

Round 1

log1

Round 2

VM Recovery

Checkpoint

log3

Round n

Stop and copyTransfer log n

Replay log n

Take over A

Waiting and chasing phase

……

®CR/TR-Motion: Migration Downtime

• Our approach reduced migration downtime by 72.4% in average compared to

pre-copy approach

0

50

100

150

200

250

300

Daily use Kernel-build Static web app

Dynamic web app

UnixBench

Downtime(ms)

CR/TR-Motion

Pre-copy

0

10

20

30

40

50

60

70

80

90

100

Daily use Kernel-build Static web

app

Dynamic

web app

UnixBench

Total migration time (s)

CR/TR-Motion

Pre-copy

• Our approach reduces the total migration

time by 31.5% in average compared to

Pre-copy

®

CR/TR-Motion: Total Data Transferred

• CR/TR-Motion reduces

synchronization traffic

by 95.9% in average

• This improvement

brings great benefit

when our migration

scheme is applied in

low-bandwidth WANs

daily use 0.48 (0.04) 38.54 (2.1) 98.8%

kernel-build 0.53 (0.06) 152.44 (8.2) 99.6%

static web app 8.34 (0.21) 228.99 (9.4) 96.4%

dynamic web app 36.4 (0.96) 288.05 (12.2) 87.4%

unixbench 2.59 (0.22) 113.38 (6.4) 97.7%

0

100

200

300

400

500

600

700

800

900

Daily use Kernel-build Static web

app

Dynamic

web app

UnixBench

Total Data Transferred (MB) CR/TR-Motion

Pre-copy

®Outline



– Live Migration




• Conclusions

®Power Management - Motivation

• Reduce power consumption with little performance penalty

• User requirement is various– Server – Average power consumption should fit the budget

– Desktop – User experience should be kept

– Laptop – Prolong battery lifetime

• Virtualization brings challenges– Guest OS is blind to the hardware features

– VMM lacks the device PM ability – it has no device drivers

®Design of ClientVisor

• Focus on desktop virtualization

– VMs are asymmetric

– Hardware power features can be exposed to VM

• Dom0 – Domain 0, the control domain

• SOS – Service OS, background domain for

special tasks. e.g., network packet filtering

• COS – Capability OS, primary domain

interacted with users

H. Chen, H. Jin, Z. Shao, K. Yu, and K. Tian, “ClientVisor: Leverage COTS OS Functionalities for Power Management in Virtualized Desktop Environment”, Proceedings of the 2009 ACM SIGPLAN/SIGOPS International Conference on Virtual Execution Environments (VEE’09), ACM Press, March 11-13, 2009, Washington, DC, USA, pp.130-141.

®

Design of ClientVisor

Physical Platform

Xen VMM

Domain0(control domain)

SOS

COS (primary user domain)A: Px operation

B: Cx operation

C: Dx operation

D: Cx operation after coordination

E: Dx operation after coordinationCPUDevices

VADevice Driver

Coordination Logic

Device Driver OSPM

A

DE

B

FrontendDriver

BackendDriver

C

CC

®Design of ClientVisor

• Basic instruments – What guest OS does?

– Processor PM instruments – working state PM

(P-state scaling) & idle state PM (C-state

transition)

– Device PM instruments – D-state transition

• Interception policies – What VMM does?

– Passing-through – for P-state operation

– Coordination – for C-state & D-state operation

®

ClientVisor

• Preliminary of passing-through –

Exposing hardware power features

– ACPI tables

– CPUID

– Device hierarchy

Root

Bridge Endpoint Bridge

Endpoint Endpoint Endpoint Endpoint

®Performance Evaluation

• Static power consumption

– Leave the whole system in idle

10.91

16.71

15.36

13.34 13.01

0

2

4

6

8

10

12

14

16

18

Native Xen CV/Orig CV/Cx_opt CV/Cx_Timer_opt

Power (W)

• Dynamic power

consumption

– SPECpower_ssj2008 is

used as workload

23.50

28.4326.85 26.27 26.21

0.00

5.00

10.00

15.00

20.00

25.00

30.00

Native Xen CV/Orig CV/Cx_opt CV/Cx_Timer_opt

(a) Overall

Power (W)

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

Load Level

Performance (ssj_ops)

10

15

20

25

30

35

40

Power (W)

Native Xen CV/Orig CV/Cx_opt

CV/Cx_Timer_opt Native Xen CV/Orig

CV/Cx_opt CV/Cx_Timer_opt

Balance of power and

performance

Cx mapping optimization – Change Cx operation

of port I/O way to MWAIT way

Timer optimization – Disable some timer

handlers when CPU resides in Cx

®Outline



– Live Migration


–Memory Virtualization


• Conclusions

®

Dynamic Memory Balancing for Virtual Machines

• Motivation

– Allocating appropriate machine memory to a VM is hard

• Memory requirement varies during running

• OS only reports the amount of used/free memory

• The amount of actively used memory is more important

– If we know the relationship between memory allocation size and

performance gain/loss

• Idle or inactive memory can be reclaimed without notable performance

loss

• Better memory resource utilization

– Ballooning

• The amount to increase/decrease is typically specified manually

®


• Dynamic memory balancing

– LRU-based predictor

– Memory growth prediction

– Automatic memory resizing

VM1

Mon

LRU Hist. LRU Hist.

VM2

Mon

balancer

estimator

Controller

VMM

Data store

inflate/deflate

WSS

W. Zhao and Z. Wang, “Dynamic Memory Balancing for Virtual Machines”, Proceedings of the 2009 ACM SIGPLAN/SIGOPS International Conference on Virtual Execution Environments (VEE’09), ACM Press, March 11-13, 2009, Washington, DC, USA, pp.21-30.

®


• Estimation Accuracy (within Xen)

– VM is allocated with 214MB

Monotonic (40 ~ 170 MB) Random (40 ~ 170 MB)

®Outline



– Live Migration




• Conclusions

®Challenge of Desktop Virtualization

• User experience

– Fast, convenient, mobility

• Security

– Safeguard user private data

• Stability

– Reliability of the virtual desktop environment

• Serviceability

– Efficient use of CPU and memory resources

X. Liao, H. Jin, L. Hu, and H. Liu, “Towards Virtualized Desktop Environment”, Concurrency and Computation: Practice and Experience, John Wiley & Sons, Ltd (accepted)

®

Xen

server

Xen

server

……

AP

P S

erv

er

VCM

Thin

Client

PDA

Data Server

Internet

Domain 0 Domain U

Xen

Virtualized

PC

System Architecture of Virtual Desktop

®

Save & Restore (Checkpointing)

• Multi-VM collaborative save & restore

– Recoverable long-running desktop applications

– User environment mobility

– High availability

• Multi-host checkpointing

– Checkpoint synchronization (Lamport clocks)

– Transparent rolling checkpoints (Copy-on-write)

– Memory image saving optimization

®Virtual Appliance

• USB devices and

printers on the

client can be

accessed by the

remote

application on a

local network or

the Internet

App Server

client

remote desktop delivering

Plug in

mount

Network

access

USB device

®

VM Life Cycle Management

• Role-based life cycle monitor

scheme

• VM suspending management

• VM process priority policy

• VM template life cycle

management

• VM checkpoint life cycle

management

®

All-in-one Desktop Environment

®Outline



• Conclusions

®Conclusions

• As the technology base of cloud computing, virtualization technology provide– Support new architectures, devices

– High Utilization of IT facilities

– High Manageability

– Highly secure and isolate guaranteed environment

– Maintain good user experiences

• Challenges still exist in virtualization technology– Scheduling

– Live Migration


– Memory/IO Virtualization


– ……

®

Thank you!

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