Server Virtualiza-tion

Elaborated by:Maroua AISSA

Youssef HACHANI

Academic year : 2012/2013

OutlineIntroduction

I. VirtualizationII. Server VirtualizationIII. Server Virtualization’s Use domainIV. Server Virtualization’s TypesV. Server Virtualization’s Benefits

& PerformancesVI. Server Virtualization’s Limitations

Conclusion2

Introduction

• Virtualization is a big opportunity pre-sented today to solve a very big amount of problems.

• Virtualization is now all the rage.

• All servers in nearing end of life are now replaced by a virtual one.

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Virtualization (1/2)• Virtualization is the creation of a virtual version

of something, such as an operating system, a server, a storage device or network resources.

‘Nonvirtualized’ systemA single OS controls all hardware platform re-sources

‘Virtualized’ systemIt makes it possible to run multiple Virtual Containers on a single physical platform

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Virtualization (2/2)

Why virtualizes?• More efficient HW utilization• Long-term matching resources & needs• Quick and light server provisioning • Testing & Troubleshooting• More effective redundancy• HW maintenance w/o app downtime• Disaster Recovery (snapshot)

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Server Virtualization (1/2)• Server virtualization enables you to run multiple

virtual machines simultaneously on a single physical

server.

• Anything you can do with a physical machine you can do with a virtual machine. The only difference is that you can’t touch it. • Many computers operate at only 10-15% of their total computing capacity, leaving IT resources untapped and unusable; with server virtualization you can increase utilization to as much as 85%. That’s intelligent usage of IT recourses!

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Server Virtualization (2/2)• Server virtualization is the masking of server resources, including the number and iden-tity of individual physical servers, processors, and operating systems, from server users.

• The server administrator uses a software application to divide one physical server into multiple isolated virtual environments.

•The virtual environments are sometimes called virtual private servers, but they are also known as guests, instances, containers or emulations.

Server Virtualization’s Use domain

These following might be good choices for

virtualization: Web servers ,File servers , Database servers ,E-mail servers , Applications servers

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Server Virtualization’s Types (1/9)

• There are three methods to virtualize the server: oFull virtualization (Hardware Emula-

tion) o Para-virtualization oOperating System (OS) virtualization.

• While all the three modes have one physi-cal server acting as host and the virtual servers as

guests, each of the methods allocates server resources differently to the virtual space.

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1. Full virtualization• Full virtualization uses a special kind of soft-

ware called an hypervisor. • The hypervisor interacts directly with the

physical server's CPU and disk space.• It serves as a platform for the virtual servers'

OSs. • The hypervisor keeps each virtual server com-

pletely independent and unaware of the other virtual

servers running on the physical machine. • Each guest server runs on its own OS .

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Server Virtualization’s Types (2/9)

Full virtualization architecture:

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Server Virtualization’s Types (3/9)

Full virtualization

Full virtualization drawback :

The drawback with this approach is that we are adding another heavy layer of software between the operating system and the hardware, so we will notice slower performance. But if we are consolidating various under-used servers to save space and energy, this should not be so much of a concern.

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Server Virtualization’s Types (4/9)

2. Para-virtualization• The para-virtualization approach is a little dif-

ferent. • Unlike the full virtualization technique, the

guest servers in a para-virtualization system are aware

of one another. • A para-virtualization hypervisor doesn't need

as much processing power to manage the guest OSs, be-

cause each OS is already aware of the demands the

other Oss are placing on the physical server. • The entire system works together as a cohe-

sive unit.

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Server Virtualization’s Types (5/9)

Para-virtualization architecture:

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Server Virtualization’s Types (6/9)

Para-virtualization

3 . Operating System (OS) virtualiza-tion

• An OS-level virtualization approach doesn't use an

hypervisor at all. • Instead, the virtualization capability is part of

the host OS, which performs all the functions of a

fully virtualized hypervisor. • The biggest limitation of this approach is that

all the guest servers must run the same OS. • Because all the guest operating systems must

be the same, this is called a homogeneous environ-

ment.

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Server Virtualization’s Types (7/9)

Os-virtualization architecture:

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Server Virtualization’s Types (8/9)

OS virtualization

Which method is best? That largely depends on the network administrator's

needs. • If the administrator's physical servers all run on the

same OS, then an OS-level approach might work best. OS-

level systems tend to be faster and more efficient. • If the administrator is running servers on several

different OSs, para-virtualization might be a better choice. One potential drawback for para-virtualization sys-

tems is support , the technique is relatively new and only a

few companies offer para-virtualization software. More

companiessupport full virtualization.

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Server Virtualization’s Types (9/9)

Server Virtualization’s Ben-efits

& Performances (1/3)There are many reasons companies and organiza-tions are investing in server virtualization :

• Reduce hardware cost by up to 50% (by reduc-ing the number of servers)

• Reduce operational cost by up to 70% (energy bills, space leasing )

• Use less power, generate less heat, take up less space, and consume fewer resources.

• Deploy machines much faster by imaging in-stead of

building from scratch .18

• Eliminate downtime due to hardware mainte-nance.

• Insure flexibility : we can move data from that virtual

machine to another, without having to shut any-thing

down.• Provides load balancing by distributing the load dynamically to other servers, With load balancers,managing this change is automatic.• Provides higher availability independent of

hardware,operating system, and applications by ensuring continuous availability against server failures.

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Server Virtualization’s Ben-efits

& Performances (2/3)

• Establish Isolation : Each virtual machine is isolated

from other virtual machines on the same server to avoid

problems.

• Implements migration provides the ability to move live applications automatically from one physical server to another with no interruption in service.

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Server Virtualization’s Ben-efits

& Performances (3/3)

Server Virtualization’s Limitations

• For servers dedicated to applications with high demands

on processing power, virtualization isn't a good choice.

• Too many virtual servers could impact the server's ability

to store data.• Too many virtual servers could impact the server's

ability to store data.• It's only possible to migrate a virtual server from

one physical machine to another if both physical ma-

chines use the same manufacturer's processor.

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Conclusion

As server virtualization technology advances, the need for huge data centers could decline.

Here we can see the obvious need of network storage which also a related term in resource optimiza-tion of IT infrastructure and talking about these tech-nologies lead us to cloud computing.

It's not an exaggeration but virtual servers could lead to a complete revolution in the computing

industry.

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