1

Buddhika Siddhisena Co-Founder & CTO

THINKCube SystemsMember of LKLUG

VirtualizationThe future of computing

2

What is Virtualization?

3

What is Virtualization – Short

● Simple term word for a simple idea ● Run multiple “Operating System” instances

(Virtual Machines) on one physical computer● Virtualize the same OS or different OSes● Encapsulates a series of buzz words – Hypervisor,

Para virtualization, Virtual Machine, Emulation,Simulation

4

WHAT is Virtualization Technology

● Virtualization Technology (VT) is an old technology thathas been revitalized recently, thanks to faster processorincrease in processing power.

● Virtualization is often achieved by either totally orpartially emulating the processor, BIOS and otherhardware devices.

● Emulating a completely different processor architectureis much slower since CPU instructions need to beemulated, compared to a native emulation.

● Guest OS is unaware of the emulation and is led tobelieve that it has the resources of the entire machineunder its control.

5

WHAT is Virtualization Technology

6

Some popular Emulators● Qemu is an FOSS x86/x86_64,ARM,PowePC etc. CPU emulator.

● Kvm is an extended version of Qemu to support hardware virtualization

● Bochs is an x86/x86_64 emulator that is FOSS

● Mac-on-Linux is a PPC emulator which uses native cpu emulation

● UML (User Mode Linux) enables a Linux kernel to run inside anotherLinux system as a user space application.

● PearPC is an Open Source PPC G4 emulator.

● VirtualBox is now Open Source

●VMWare a commercial, free for personal user, x86 emulator that usesnative cpu emulation

7

Why Virtualize?

8

Why Virtualize - Simply

Save Money $$$

9

WHY Virtualize (Advantages)

● Better utilization of hardware. Today on anaverage, Servers run at less that 15% utilization.

● Better scalability. Dynamic scalability.

● Better maintainability. Lesser down time.

● Better fault tolerance.

● Better deployment / roll out. ISP now providevirtual root hosting within minutes.

10

Who uses Virtualization?

11

● Amazon EC2 , Google AppEngine (CloudComputing)

● Data Centers● Hosting Providers - Virtual Server● NOC● Desktop Users● You and Me

12

Para Virtualization (Xen)

● In Para-Virtualization the Guest OS is ported to an idealplatform.● The Hypervisor platform provides an API which themodified kernel of the GuestOS ends up calling when tryingto access hardware.● Device drivers are virtualized by running the part thatinteracts with the device (physical driver) in a separatedomain known as Domain0.● Virtual environments are created in a separate DomainUthat doesn't have direct access to hardware.●DomainU kernels communicate with the Domain0 kernelto access hardware.

13

Para Virtualization: Xen

● Xen runs at ring 0 where the normal OS would run

● Xen starts guestOS domain0 and domainU at ring 1

● User applications of the guestOS runs at ring 3

14

Advantages of Para-Virtualization

High performance, often close to native speed, slowest being8% of native speed.

15

Advantages of Para-Virtualization

Live migration of a VM to another physical machine with onlya few milliseconds of downtime (<100ms).

16

Disadvantages of Para-Virtualization

● Guest OS should be modified to support the Para-Virtualizationplatform. Fortunately this only requires the kernel to be ported tothe platform and the applications can remain untouched. Not aproblem for an Free/Open Source OS. Now with direct hardwaresupport using Intel's VT / AMD's Pacific.● Currently X-windows only works at on Domain0 and fails at otherdomains as it requires access to the video card hardware. It is stillpossible to run X applications that is within a DomainU VM byusing a remote desktop app such as VNC. Again not a problem withVT technlogies.

17

Enter FULL virtualization(Hardware virtualization)

Intel (Intel-VT) and AMD (AMD-V) nowfully support virtualization at a hardware

levelLinux Kernel officially supports Full VT via

kvm

18

Software virtualization(multi-tenant virtualization)

More cost effective and scalableModify Application to support multiple

instancesSecurity is the applications responsibility

19

Thank You

Use the force, read the source!