CLOUD TECHNOLOGY - VIRTUALIZATION

Spencer Lin

What is a Virtual Machine?

A virtual machine (VM) is a software computer that, like a physical computer, runs an operating system and applications. Every virtual machine has virtual devices that provide the same functionality as physical hardware and have additional benefits in terms of portability, manageability, and security.

What is Virtualization? Virtualization means creation of a virtual

version of a device or resource, such as a server, storage device, network, and software (including operating system). This allows physical hardware resources to be shared by multiple applications (VMs).

Hypervisor: virtual machine manager (VMM) A program that allows multiple operating

systems to share a single hardware host. Example: VMware ESXi, Microsoft Hyper-V,

and KVM Non Virtual Machine and VM Configurations

Advantages of VirtualizationReduce capital and operating costsDeliver high application availabilityMinimize or eliminate downtime. Increase IT productivity, efficiency, agility and

responsivenessSpeed and simplify application and resource provisioningSupport business continuity and disaster recoveryEnable centralized management

Types of Hypervisor

1. Type 1 Bare-metal Hypervisor: runs directly on

the system hardware. Examples: VMware ESXi, Citrix

XenServer.2. Type 2

Hosted Hypervisor: runs on a host operating system.

Examples: VMware Workstation, VMware Fusion, Virtualbox, Microsoft Hyper-V.

Difference Between Type 1 and 2 Hypervisors

Server Virtualization – What is it?

Server virtualization is a virtualization technique that presents a physical server as if partitioned into a number of small, virtual servers with the help of virtualization software. In server virtualization, each physical server runs multiple operating system instances at the same time.

Traditional Storage

Traditional storage: Directly attached to servers and

cannot be shared beyond the physical server.

Difficult for administrators to assign storage requirements for each application.

All applications running on physical server are forced to use the same storage, with same storage characteristics.

Solution to Traditional Storage - Storage Virtualization

Solution to traditional storage is storage virtualization:

Adds a new layer of software and/or hardware between storage systems and servers.

A centralized storage enables servers to share centralized resources, so that applications no longer need to know on which specific drives, partitions or storage subsystems their data resides.

Storage virtualization is commonly used in storage area networks (SANs).

Storage Area Network (SAN)

Storage Area Networks are the most comprehensive centralized storage solution. It allows for true storage sharing since data is stored at the block level. This means applications, including the OS can directly access the storage device as if it was locally attached. Each block can be controlled as an individual hard drive. These

Blocks are controlled by server based operating systems and each block can be individually formatted with the required file system.

Network Virtualization – Standard vSwitch VMware Network Virtualization provides “virtual networks” to virtual machines similar to how server virtualization (hypervisor) provides “virtual machines” to the operating system.

A network standard switch, virtual switch, or vSwitch, is responsible for connecting virtual machines to a virtual network. A vSwitch works similar to a physical switch, with some limitations, and controls how virtual machines communicate with one another. vSphere Standard vSwitch

Network Virtualization – Distributed vSwitch Distributed vSwitch, which

are also known as VMware vDS, enable more features than standard vSwitches, sometimes called VMware vSS.

A standard vSwitch works within one ESXi host only.

Distributed vSwitches allow different hosts to use the switch as long as they exist within the same host cluster

vSphere Distributed vSwitch

Summary A virtual machine (VM) is a software computer that, like a physical computer, runs an operating system and applications.

Virtualization means creation of a virtual version of a device or resource, such as a server, storage device, network, and software (including operating system).

Two types of Hypervisor: Bare-metal Hypervisor and Hosted Hypervisor. Server virtualization is a virtualization technique that presents a physical

server as if partitioned into a number of small, virtual servers with the help of virtualization software.

Solution to traditional storage is storage virtualization which adds a new layer of software and/or hardware between storage systems and servers.

Network Virtualization provides “virtual networks” to virtual machines similar to how server virtualization (hypervisor) provides “virtual machines” to the operating system.

Virtualization and the Cloud

The encapsulation offered in virtualization and the mobility found in this technology enables a live virtual machine to be moved with no downtime for the application – the dependency on the Cloud infrastructure is minimal.

Virtualization powers cloud computing and increases IT scalability, agility, flexibility and performance while creating a major cost savings. With server, storage, and network virtualization, cloud computing enables companies to react faster to the needs of business, while driving greater operational efficiencies.

References"Virtualization." VMware. N.p., n.d. Web. 14 Oct. 2015. <http://www.vmware.com/virtualization.html>."CLOUD COMPUTING AND VIRTUALIZATION." JAN KREMER CONSULTING SERVICES. N.p., n.d. Web. 14 Oct. 2015. <http://jkremer.com/White%20Papers/Cloud%20Computing%20and%20Virtualization%20White%20Paper%20JKCS.pdf>.Freeman, Bill. "Best Hardware for Server Virtualisation." TouchPoint. N.p., 17 Feb. 2015. Web. 20 Nov. 2015. <http://touchpoint.com.au/blog/best-hardware-for-server-virtualisation/>.Siebert, Eric. "Selecting CPU, processors and memory for virtualized environments." TechTarget. N.p., n.d. Web. 20 Nov. 2015. <http://searchservervirtualization.techtarget.com/tip/Selecting-CPU-processors-and-memory-for-virtualized-environments>."Centralized Storage." Netcal. N.p., n.d. Web. 20 Nov. 2015. <http://www.netcal.com/centralized-storage/>.Jorgenson, Petra. "Virtual Networking 101: Understanding VMware Networking." Pluralsight. N.p., 30 May 2012. Web. 20 Nov. 2015. <http://blog.pluralsight.com/virtual-networking-101-understanding-vmware-networking>.Davis, David. "VMware's standard and distributed virtual switches: What resellers need to know." TechTarget. N.p., Feb. 2010. Web. 20 Nov. 2015. <http://searchitchannel.techtarget.com/tip/VMwares-standard-and-distributed-virtual-switches-What-resellers-need-to-know>."How do switches, vSwitches and distributed vSwitches differ?" TechTarget. N.p., 11 June 2013. Web. 20 Nov. 2015. <http://searchvmware.techtarget.com/photostory/2240185944/Getting-VMware-terminology-straight/9/How-do-switches-vSwitches-and-distributed-vSwitches-differ>.

Technical Details

Server Virtualization – Software RequirementsSoftware Vendors: VMware vSphere, Microsoft Hyper-V, Citrix XenServer More similarities between all of the software vendors than differences All those software platforms have the ability to manage processor, memory, network,

and disk resources. All support both Microsoft Windows and Linux operating environments, and some

support Solaris Unix as well The only possible difference between software vendors are performance, reliability,

and advanced management.

VMware is obviously the leader in virtualization platform

Server Virtualization – Hardware Requirements Choosing the best hardware for virtualization begins with a server’s memory and

CPU. The lack of memory or CPU can directly affect performance.Memory: Memory is often the most limiting factor in the number of virtual machines a

server can host. Ensuring an adequate amount of fast RAM plays a huge role in the server’s virtualization capabilities.

CPU: Selecting a CPU with multiple cores can significantly increase performance and

throughput. There are two major CPU brands in the market, Intel and AMD. Both Intel and AMD have integrated virtualization extensions, Intel Virtualization Technology (Intel-VT) and AMD Virtualization (AMD-V).

Choosing a right CPU brand depends on your current environment. If your current servers already use a particular brand, it is a good idea to just stick with it because one VM running on Intel can not be moved to AMD, and vice verse.

Network Virtualization - Standard vSwitch features

The standard vSwitch offers following features: Layer 2 forwarding 802.1Q VLAN tagging Multicast support EtherChannel Load balancing Tx rate limiting Port security CDP ……..

Network Virtualization – Distributed vSwitch featuresUnlike standard vSwitches, which can be managed from the local host, DvSwitches must be created and controlled through vCenter Server. VMware vCenter Server provides centralized management of vSphere virtual

infrastructure. IT administrators can ensure security and availability, simplify day-to-day tasks,

and reduce the complexity of managing virtual infrastructure).

Distributed vSwitch offers all features standard vSwitch have + following features: Centralized configuration for all network switch ports, across the entire virtual

infrastructure. Private VLANs. Support for third-party switches (with the only option today being the Cisco Nexus

1000-V).