Server And Hardware Virtualization_Aakash1.1

Aakash Agarwal Email: [email protected]

Overview on Server And Hardware Virtualization

Components

This PPT is Self-prepared from Open Source documents available on Internet or company's website. The PPT includes no NDA information and is to share knowledge in the group. It is completely Monetary FREE session. The Images and Logo's used in this PPT are only to reference the technology not for Advertisement or any kind of Promotion by any company. The Views shared in this PPT are personal views are not referenced to any company where preparer/presenter of the PPT works or Worked. View Shared in this PPT are Personal View NOT Cisco or VMWare views. - Please contact Aakash Agarwal for any suggestions – Aakash Agarwal ([email protected])

Training Prerequisites

• Understanding the Basic Network Concepts

• Understanding & Experience with Layer 2 Switching

Targeted Audience

• Network Engineer working in Data Center who needs to get an overview of other side of the river

• A student trying to understand Virtualization • Anyone ;)

Agenda

• What is Virtualization

• Why Virtualization

• VMware Server Virtualization Components

• VMware Virtualized Host Interfaces

• VMware Virtualized Physical Interfaces

• VMware Virtualized Host Networking Components

• Cisco UCS And Components

What/Why

Virtualization

What/Why Virtualization

• Virtualization is the creation of a virtual (rather than Physical) version of something, such as an operating system, a server, a storage device or network resources. – Server virtualization

– Network virtualization

– Storage virtualization

http://searchservervirtualization.techtarget.com/definition/virtual

http://searchcio-midmarket.techtarget.com/definition/operating-system

http://whatis.techtarget.com/definition/0,,sid9_gci212964,00.html


• What is Virtualization – Virtualization is a layer that decouples physical hardware

from Operating System to deliver high flexibility.

• What are Virtual Machines - It is a representation of a Physical machine by

Software. it has it’s own set if Virtual hardware (e.g. Ram, CPU, NIC and whatever you can name) up on which OS and applications are loaded.


• Why Virtualization –

VMware Server Virtualization Components


• Server virtualization Component s:

– Hypervisor - Virtual machine manager, is a program that allows

multiple operating systems to share a single hardware host.

– Virtual Machine (VM) - A virtual machine (VM) is a software

implementation of a computing environment in which an operating system (OS) or program can be installed and run. Or in Simple words Virtual instance of Physical Computer Machine.


1 vMotion Moves VMs Across Physical Ports -

from one Physical Hardware to another


2 VM moved to different hardware with no

downtime

VMware Virtualized

Host Interfaces

VMware Virtualized Host Interfaces

VMware Virtualized Host Interfaces • Virtual Interfaces: To start with basics on the interfaces, VMware uses

5 types of Virtual Ethernet Adapters you may come across in a VM. However in most cases only 3 are used:

• Vmxnet Interface– The VMXNET virtual network adapter has no physical

counterpart. VMXNET is optimized for performance in a virtual machine. Because operating system vendors do not provide built-in drivers for this card, you must install VMware Tools to have a driver for the VMXNET network adapter available.

VMware Virtualized Host Interfaces Using TSO and LRO on physical and virtual machine NICs improves the performance of ESX/ESXi hosts by reducing the CPU overhead for TCP/IP network operations. The host can use more CPU cycles to run applications.

• TSO (TCP Segmentation Offload) - If TSO is enabled on the transmission path, the NIC

divides larger data chunks into TCP segments. If TSO is disabled, the CPU performs segmentation for TCP/IP. TSO is referred to as LSO (Large Segment Offload or Large Send Offload) in the latest VMXNET3 driver attributes. By default, a host is configured to use hardware TSO if its NICs support it.

VMware Virtualized Host Interfaces • LRO (Large Receive Offload) - LRO reassembles incoming network packets into larger

buffers and transfers the resulting larger but fewer packets to the network stack of the host or virtual machine. The CPU has to process fewer packets than when LRO is disabled, which reduces its utilization for networking. LRO is enabled by default on VMXNET2 (Enhanced) and VMXNET3 devices.

Reference Documents – Poor TCP performance might occur in Linux virtual machines with LRO enabled (1027511) Understanding TSO and LRO in a VMware environment

http://kb.vmware.com/selfservice/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=1027511

http://kb.vmware.com/selfservice/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=1027511

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2055140


• Jumbo Frames:

VMware Virtualized Host Interfaces • vlance Interface – An emulated version of the AMD 79C970 PCnet32 LANCE NIC,

an older 10 Mbps NIC with drivers available in most 32-bit guest operating systems except Windows Vista and later. A virtual machine configured with this network adapter can use its network immediately.

• e1000 Interface - A virtual device that provides strict emulation of the Intel

E1000 Ethernet adapter. This is the virtual Ethernet adapter used in 64-bit virtual machines. It is also available in 32 -bit virtual machines.

VMware Virtualized Host Interfaces • vswif Interface – A paravirtualized device similar to vmxnet that is used only by

the ESX Server service console.

• vmknic - The virtual kernel NIC (vmknic) is used by the hypervisor for management,

the vmknic is used by the TCP/IP stack that services VMotion, NFS and software iSCSI clients.


• All five of the virtual network devices share the following characteristics: • They have their own MAC addresses and unicast/multicast/broadcast filters. • They are strictly Layer 2Ethernet adapter devices.

• The speed and duplex settings found in physical networking are not relevant in the virtual network, because all the data transfer takes place in the host system’s RAM, nearly instantaneously and without the possibility of collisions or other signaling-related errors.

VMware Virtualized Physical Interfaces

VMware Virtualized Physical

Interfaces

VMware Virtualized

Host Networking

VMware Virtualized Host Networking

• Virtual switches are the key networking components in VMware Infrastructure. A virtual switch is “built to order” at run time from a collection of small functional units. Some of the key functional units are:

• The core Layer forwarding engine. So no Layer 3 SVIs etc • VLAN tagging, stripping, and filtering units • Layer 2 checksum, and segmentation offload units

• This modular approach has become a basic principle to be followed in future development, as well. Modular design is that VMware and third-party developers can easily incorporate modules to enhance the system in the future.

VMware Virtualized Host Networking • A Virtual Switch Is Similar to a Physical Switch: A virtual switch, as implemented in ESX

Server, works in much the same way as a modern Ethernet switch. Performs the following functions:

• MAC:port forwarding table • Looks up each frame’s destination MAC when it arrives – Destination Lookup • Forwards a frame to one or more ports for transmission • Avoids unnecessary deliveries (in other words, it is not a hub) – Unicast

forwarding • Access Port and Trunked Port same as Physical Switches • STP NOT needed - VMware Infrastructure enforces a single-tier networking

topology. In other words, there is no way to interconnect multiple virtual switches, thus the network cannot be configured to introduce loops. As a result,

Spanning Tree Protocol (STP) is not needed and is not present.


• Virtual Ports: The ports on a virtual switch provide logical connection points among virtual

devices and between virtual and physical devices. You can think of them as virtual RJ-45 connectors. Each virtual switch can have up to 1,016 virtual ports, with a limit of 4,096 ports on all virtual switches on a host.

• Uplink Ports: Uplink ports are ports associated with physical adapters, providing a connection

between a virtual network and a physical network.

• Port Groups: As important as they are in VMware Infrastructure virtual networking, port

groups do not correspond exactly to features commonly found in physical networks. The closest counterpart is the SmartPort feature offered in some Cisco switches. You can think of port groups as templates for creating virtual ports with particular sets of specifications. You can create a maximum of 512 port groups on a single host.

Port groups are user-named objects that contain enough configuration information to provide persistent and consistent network access for virtual Ethernet adapters:

• Virtual switch name • VLAN IDs and policies for tagging and filtering • Teaming policy • Layer 2security options • Traffic shaping parameters

Cisco UCS &

It’s Components

This PPT is Self-prepared from Open Source documents available on Internet or company's website. The PPT includes no NDA information and is to share knowledge in the group. It is completely Monetary FREE session. The Images and Logo's used in this PPT are only to reference the technology not for Advertisement or any kind of Promotion by any company. The Views shared in this PPT are personal views are not referenced to any company where preparer/presenter of the PPT works or Worked. View Shared in this PPT are Personal View NOT Cisco or VMWare views. Please contact Aakash Agarwal for any suggestions – Aakash Agarwal ([email protected])

Server And Hardware Virtualization_Aakash1.1

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