This document provides an overview of virtualization concepts and VMware vSphere features. It begins with defining key virtualization building blocks like hypervisors, virtual machines, and virtual switches. It then covers ESXi architecture, vCenter functionality, and advanced features like vMotion, HA, and vNetworking. The document aims to give attendees a deep understanding of virtualization and how vSphere addresses various virtualization challenges.

1. www.gslab.com
Amit Agarwal
Date – 18th July, 2016
Virtualization -101 A Deep Dive

2. About Me
• 4 years of experience working with Virtualization Products.
• VMware Certified Associate and Professional – DataCenter Virtualization.
• Contributor to the book – Mastering vSphere PowerCLI.
• Active member of VMware Community and VMware user group(VMUGs).
• Working with GSLab for the past 1 year in Cloudgenix Project as Senior QA.
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3. Agenda
• The basic principles and technology of virtualization
• Anatomy of Hypervisor (ESXi)
• Anatomy of a virtual machine
• vCenter usage and some advance vSphere features
• vNetworking concepts
• A brief on vSphere powerCLI Scripting and Usage
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4. Virtualization : Basic Building Blocks
• Hypervisor :- Two Types –
- BareMetal (ESXi)
- Hosted (VMware Workstation, Virtual Box)
• ESXi contains VMkernel which is the 64 bit microkernel that directly handles memory
and CPU.
• Hardware access uses modules (drivers) adapted to work with VMkernel.
• VMkernel does not run VMs directly, VMM does that.
• Virtual Machine Monitor (VMM) :- It is a process that runs in the VMkernel which
virtualizes the guest OS instructions and manages memory.
- The VMM passes storage and network I/O requests to the VMKernel.
- There is a VMM for each virtual CPU assigned to the virtual machine.
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5. Virtualization : Basic Building Blocks
• Rings :-
- x86 CPUs provide a range protection levels called Rings in which
code can execute.
- Ring ‘0’ has the highest level priviledge and is where the operating
system kernel normally runs.
• Non-Virtualized Systems – OS runs at Ring 0 and owns the Hardware.
Applications run in Ring 3 with less privileges.
• Virtualized Systems – VMM runs at Ring 0 which fools the Guest OS into
thinking that they are running in Ring ’0’ – Full Virtualization.
Newer CPUs (Intel VT-x) uses a new privilege level called Ring ‘-1’,
and puts VMM There which results in better performance.
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6. • CPU Scheduler :-
- Schedules VMs virtual CPU time on the host physical CPUs.
- Scheduling many vCPUs to limited pCPUs can be very challenging ,
for this VMware uses a proportional-share based algorithm.
- Optimizes placement of vCPUs onto different sockets to maximize
cache utilization.
• Memory Virtualization :-
- VMkernel manages all VM memory.
- It creates a contiguous addressable memory space for the VM,
- This memory space has the same properties as the virtual address space
presented to the applications by the guest operating system.
- This also helps for each VM to run in complete isolation.
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Virtualization : Basic Building Blocks

7. Complete ESXi Architecture
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8. Anatomy of a Virtual Machine
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• Representation of a physical
machine by software that has its
own set of virtual hardware
upon which an OS and Apps can
be loaded.
• Its basically a set of discrete files
located on the datastore
accessible to the ESXi Host.
• When VM is powered on, the
host mounts the virtual disk.

9. vCenter – What is it?
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VMware vCenter Server is the central point for
configuring, provisioning, and managing
virtualized IT environments.
vCenter Architecture

10. vCenter – Do I really need it?
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• Use vCenter Server to centrally manage your hosts and virtual machines instead of
logging directly in to each host.
• It inherits thr group roles from AD, hence provide ease in Access Control.
• Many Advance vSphere features are only supported in vCenter like –
- vMotion
- High Availability
- Fault Tolerance
- DRS
• It allows us to use the inventory views to organize inventory objects(Storage,
Networks, templates etc) in a meaningful way.

11. Advance features – vMotion
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• Source and Destination Host
must have :
- Visibility to all storage used by
the virtual machine
- At least a Gigabit Ethernet
network.
- Access to the same physical
network.
- Compatible CPUs.
Enhanced vMotion lets you migrate
without a shared storage and same
CPU characteristics.

12. Advance features – High Availability (HA)
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• In case of a fail-over the
virtual machine gets
migrated and is literally
restarted on one of the
remaining hosts in the
cluster.
• vCenter manages this and
uses a master-slave
architecture.
• Heartbeating is the
mechanism used by HA
to validate whether a
host is alive.

13. Nested Virtualization
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• You can expose the
Intel VT/AMD V
hardware virtualization
flags to a guest VM
riding on VMware.
• This VM can then host
its own VM’s.
• There will be a
performance hit.

14. www.gslab.com
vNetworking

15. FinanceEngineering
Physical Network – Design
Comp 2 Comp 3 Comp 4Comp 1
Physical Switch
Comp 6 Comp 7 Comp 8Comp 5
Physical Switch

16. FinanceEngineering
Physical Network – with VLAN
Comp 2 Comp 3 Comp 4Comp 1
Physical Switch

17. Components in vNetworking
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18. Components in vNetworking
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• Virtual Network Adapters
- vNic – VM’s interface to the network
- vmknic – vSphere hypervisor’s interface to network(NFS, vMotion, FT)
• Physical Network Adapter
- pNic or vmnic – for communicating with entities outside ESXi host.
• Virtual Switch
- vSwitch : forwards packets between vNics, vmknics and pNics.
• Port Group
- Group of port sharing the same configuration (e.g vlan)
• Uplinks : connections to physical switches
• NIC team : a group of pNnics connected to the same physical network.

19. HOST 2 (ESX)HOST 1 (ESX)
Virtual Network and Communication
VM1 VM2 VM4
vSwitch
Physical Switch
3
2
1
VM3
1
2
4
3 5
6
7
Trunk Trunk

20. Physical Switch vs Virtual Switch
Similarities -
• Maintains MAC Address tables.
• Lookup each frame’s destination MAC upon arrival.
• Forward frames to one or more ports.
• Avoid unnecessary deliveries.
Differences -
• Cannot connect to virtual switch together.
• As a result of this they do not require Spanning Tree Protocol.
• Forwarding table data is unique to each virtual switch.
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21. vSphere Distributed Switch - vDS
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• Centrally managed, Datacenter-wide switch
• Enhanced network monitoring and troubleshooting (RSPAN &
ERSPAN, SNMPv3.0)
• Maintain Network runtime state of VMs as they move across
HOSTs (Network vMotion)
• Here we will have:
DV Port Group - offer additional features - administrators can define
not just outbound traffic shaping, but inbound traffic shaping as well,
DV Uplink

22. Complete Picture - vDS
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23. An Introduction to vSphere PowerCLI Scripting
• vSphere powerCLI can automate any operation you want in your virtual infrastructure.
• Its tightly integrated
with Microsoft
PowerShell and has
400 cmdlets.
• Follows a Verb-Noun
structure, where
Verb : Action and
Noun : Object.
Ex : Get-VM, Get-VMHost
Set-VM
• It uses SOAP APIs for
connection hence
independent of UI changes.
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24. www.gslab.com
Thank you vMuch 
Go Virtualize...!!