What exactly is virtualization? Types of virtualization Current trend in virtualization How virtualization leads to Cloud Computing? Cloud Computing Stack

1. Virtualization and how it leads to cloud...
- Huzefa Husain
- https://in.linkedin.com/in/huzefaaa
- huzefaaa@gmail.com

2. Overview
• What exactly is virtualization?
• Types of virtualization
• Current trend in virtualization
• How virtualization leads to Cloud Computing?
• Cloud Computing Stack
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3. What exactly is virtualization?
• Inserting a layer of software between the machine and
traditional operating systems.
• Creating multiple logical server OS instances on one
physical piece of hardware
• All HW drivers are virtualized.
• Each virtual machine is completely independent of the
others and doesn't 'realize’ it’s virtualized.
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4. Types of Virtualization
Hosted Virtualization
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Bare-metal Virtualization

5. What is a Hypervisor?
• A hypervisor, also called a virtual machine manager (VMM),
is a program that allows multiple operating systems to share
a single hardware host.
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6. It's all about Rings
• x86 CPUs provide a range of protection levels also known
as rings in which code can execute. Ring 0 has the highest
level privilege and is where the operating system kernel
normally runs. Code executing in Ring 0 is said to be
running in system space, kernel mode or supervisor mode.
All other code such as applications running on the operating
system operate in less privileged rings, typically Ring 3.
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7. Rings in virtualization
Traditional systems
• Operating system runs in privileged mode in
Ring 0 and owns the hardware
• Applications run in Ring 3 with less
privileges
Virtualized systems
• VMM runs in privileged mode in Ring 0
• Guest OS inside VMs are fooled into thinking
they are running in Ring 0, privileged
instructions are trapped and emulated by the
VMM
• Newer CPUs (AMD-V/Intel-VT) use a new
privilege level called Ring -1 for the VMM to
reside allowing for better performance as the
VMM no longer needs to fool the Guest OS
that it is running in Ring 0.
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8. Example – Server Consolidation
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3 – server
scenario
Consolidated
server
scenario

9. Example – Server Consolidation
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10. Example – Server Consolidation
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11. The benefits of Going Virtual (Thebusinessperspective…..)
• Simplify data center – to create more dynamic and
flexible IT Infrastructure
• Reliability and Availability - Build up business
continuity through improved disaster recovery
solutions and deliver high availability throughout the
datacenter.
• Reduce capital expenses through server
consolidation
• Improve operating expenses through automation.
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12. The benefits of Going Virtual (Thetechnologyperspective…..)
• Efficiency: use the native hardware of the physical
machine to as great a degree as possible (without affecting
application Performance)
• Flexible Resource Allocation: Hot add vCPUs and
memory, VMFS volume grow, hot extend virtual disks, hot
add virtual disks, hot add NICs.
• Advanced Memory Management: Ability to reclaim unused
memory, de-duplicate memory pages, compress memory
pages
• Less administrative overhead: Single management
interface to control hosts and VMs
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13. Marketplace Offerings
Freely Available
• OpenVZ (Open Source)
• KVM
• VMWare Server (GSX)
• Xen 3.0 (Open Source)
Commercial
• Virtuozzo
• VMWare ESX
• Xen Enterprise
• Microsoft Virtual Server
• Virtual Iron
• RedHat Virtualization

14. Virtualization options (Citrix Xen or Vmware
ESXi)
• Xen and ESXi are two cost efficient mature
technologies in market and are “enterprise ready”.
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Citrix Xen: The virtualization
technique is called integrated
virtualization or paravirtualization.
VMware ESXi: The virtualization
technique is called full virtualization.

15. • Two main directions in virtualization:
– Full virtualization (ESXi): the VMM provides an identical
abstraction of the underlying hardware
• No changes required to the guest Oss
– Paravirtualization (Xen): the VMM provides an “almost”
identical abstraction of the underlying hardware. The
abstraction implements some new instructions to make the
machine virtualizable.
• Guest OSs need to be modified.
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16. Feature Comparison (Vmware ESXi Vs
Citrix Xen)
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Hypervisor Attributes VMware vSphere Hypervisor 5.0 Citrix XenServer 5.6 FP1
Small Disk Footprint Small disk footprint >1GB
OS Independence No reliance on general purpose operating system Relies on Linux in Dom0
management Partition
Hardened Drivers Optimized with hardware vendors Generic Linux Drivers
Advanced Memory
Management
Ability to reclaim unused memory, de-duplicate
memory pages, compress memory pages
Only uses balloning. No ability to de-
duplicate or compress pages. Does
not adjust memory allocation based
on VM usage.
Advanced Storage
Management
VMware vStorage VMFS,Storage
vMotion, Storage DRS
Lacks an integrated cluster file
system, no live storage migration,
storage features support very few
arrays
High I/O Scalability Direct driver model I/O bottleneck in Dom0
management OS
Host Resource
Management
Network traffic shaping, per-VM resource shares,
set quality of service priorities for storage and
network I/O
Lacks similar capabilities

17. Feature Comparison (Vmware ESXi Vs
Citrix Xen)
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Hypervisor Attributes VMware vSphere Hypervisor 5.0 Citrix XenServer 5.6 FP1
Performance
Enhancements
AMD RVI, Intel EPT large memory pages, universal 32-way
vSMP, VMI paravirtualization, VMDirectPath I/O, PV guest SCSI
driver
No large memory pages, no
paravirt guest SCSI device,
Requires inflexible SR-IOV
Virtual Security
Technology
VMware VMsafe™ Enables hypervisor level security
introspection Nothing comparable
Flexible Resource
Allocation
Hot add VM vCPUs and memory, VMFS volume grow, hot
extend virtual disks, hot add virtual disks Nothing comparable
Custom image creation
and management
VMware Image Builder allows administrators to create custom
ESXi images for different types of deployment, such as ISO-
based installation, PXE-based installation, and Auto Deploy.
Nothing comparable
Auto Deploy vSphere Auto Deploy enables faster provisioning of multiple
hosts. New hosts are auto provisioned based on rules defined by
user.
Nothing comparable
Management Interface
Firewall
ESXi Firewall is a service-oriented and stateless firewall that
protects the ESXi 5.0 management interface. Configured using
the vSphere Client or at the command line with esxcli interfaces.
Nothing comparable
Enhanced Virtual
Hardware
32-way virtual SMP, 1TB virtual machine RAM, Non hardware
accelerated 3D graphics, USB 3.0 device support, Unified
Extended Firmware Interface (UEFI).
8-way virtual SMP only, 32
GB RAM per virtual machine

18. VMWare Failover technology
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VMWare HA
Minimize Downtime from Server and
Operating System Failures
Data Center 1
Data Center 2
Fault Tolerance
(Active – Shadow)
Local Survivability
Enterprise Survivability
Storage
Storage

19. Current market trend in virtualization….
(Source: Gartner)
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20. Gartner Magic Quadrant

21. Market Share
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22. Client desktop virtualization
• According to Gartner:
- Professional clients using HVD will
grow from approximately 368,000 in
2008 to 70 million in 2014.
- Professional users will migrate away
from the traditional PC delivery
model, driving HVD growth.
- By 2014, 10% of professional client
install base will consist of thin clients
and diskless / repurposed PCs, from
3% in 2008.
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23. Hypervisor comparison
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24. What is Cloud?
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25. 25
Virtualization leads to Cloud Computing

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Cloud Computing Stack
Compute Compute
App Framework
Compute
App Framework
Business Logic
•Amazon
•GoGrid
•Linode
•Rackspace
•Others…
•AppEngine
•Azure
•EngineYard
•Force.com
•Heroku
•Google Apps
•Salesforce
•Taleo, Workday,
•Many others

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Thank You