Platform/Server Virtualization

How is virtual used in IT

-virtual memory

-virtual drives

-virtual CD-ROMs

What is considered virtual

anything that is spoofed or faked it can be considered virtual

How does virtualization apply

applies to system or server virtualization

What is system virtualization

the process of emulating hardware so it can be made available to multiple logical systems

How are stems that are virtualized related

each system is independent of all others

What is a virtual server

single computer that appears as an independent computer to multiple clients or guest operating systems

What does system virtualization allow for

the ability to run multiple operating systems simultaneously on a single computer

What is the traditional method

hardware that is dedicated to OS on which applications run

What is the virtualization method

software that emulates hardware which guest operating systems use as if real

Is virtualization an old concept

no

When was virtualization first introduced

in the 1960s by IBM

Why was virtualization first introduced by IBM

partition large mainframe based systems

What was the first version of virtualization

VM/370 (virtual machine facility)

When was it abanded

in the 1980s-90s

Why was it abanded

due to the inexpensive x86 servers and the popularity of client/server applications

When was virtualization support started for x86 systems

in 1998 thanks to VMware

What did VMware address in the supported version of x86 systems

to address server bloat

-low utilization/high infrastructure

-high management/ maintenance cost

-poor disaster recovery/failover protection

What are the types of virtualization archtiecture

-client based (hosted) architecture

-bare-metal (hypervisor) architecture

What is client based (hosted) architecture

-virtualization layer installed on top of an existing OS as an applications and other programs run alongside the virtualization software

What is client based (hosted) architecture also called

workstation virtualization

What does client based (hoste) architecture best allow for

support for host hardware like sound cards, usb ports, etc.

What is bare-metal (hypervisor) architecture

-virtualization layer is installed directly on the hardware

-no operating system is needed

What is more effective client based or bare metal

bare metal

What is a virtual machine (VM)

each environment available for OS installation

What is guest operating system

The operating system installed in a VM

What is host operating system

in hosted architecture, the OS in which the virtualization software runs

What is a hypervisor

the software that provides the virtualization layer in a bare metal architecture

What some of the advantages in virtualization

-flexibility

-increased reliability

-provides a consistent hardware interface regardless of underlying physical hardware

-increased capacity and scalability

-lower infrastructure cost

-reduced energy cost

What are some of the disadvantages of virtualization

-single point of failure

-complicates hardware maintenance

-harder to keep track of software and operating system

Explain the flexibility of virtualization

-can run different types of OS on the same hardware

-VMs can be easily cloned or used as templates

-VMs can be quickly moved amount servers

-can quickly create test environment

What are VMs easily cloned or used as templates

OS/HD/etc. is just a set of files that are easily copied

Explain increased relaibilty

virtual machine can be configured to automatically move from a failed server to one that is still working

-called fail-over or high availability

Explain consistent hardware interface regardless of underlying physical hardware

-can run an OS hardware that is not natively supported

-allows a server to move seamlessly between different hardware platforms without changing drivers

-enables virtual appliances

What is virtual appliances`

-instead of having to install and debug software platforms an entire installation, including OS, can be added to a virtual machine server

-completely different way of implementing services

Explain increased capacity and scalability

-virtual members of a cluster can spin up or down as needed to meet current demands

-one of the basic tenants of cloud computing

Explain infrastructure cost

-saves physical or rack space

-less hardware to maintain

-increased hardware utilization

Explain reduced energy cost

-less power consumption

-less cooling

Explain single point of failure

-if host OS crashes all VMs crash

-if host hardware fails, all VMs fail

Explain complications hardware maintenance

if you need to take the host server down multiple guests are affected

Explain harder to keep track of software and operating systems

not just looking for a box or server - could be virtualized somewhere and could have been moved automatically

What are system virtualization components

-CPU

-Memory

-Drivers and I/O virtualization

What are the types of CPU virtualization

-full virtualization

-paravirtualization

-hardware assisted

What is full virtualization of CPU

-uses binary translation to execute instructions that are non virtualizable

-offers the best isolation and most security between VMs but is complex

What is paravirtualization

-uses modified guest OS to remove non-virtualizable instructions

-poor compatibility but good performance

what is paravirtualization also called

OS assist

What is hardware assisted

-hypervisor traps non-virtualizable instructions and re-issues them to hardware in root mode which is a function of CPU enhancement

-compatibility is excellent but lower performance

What is memory virtualization

-uses virtual to physical mapping maintained by the hypervisor

-each VM thinks that it has contiguous memory space available

-standard libraries can be shared amount VMs which reduces the required memory

What is device and I/O virtualization

-involves managing the routing of I/O requests between virtual devices and the shared physical hardware

-biggest performance hit in system virtualization

What is the system virtualization futures

will continue to be a key technology through the foreseeable future

Why will system virtualization continue to be a key technology

the management and cost models are too powerfull

What will the future development likely include

-remove the requirement to do binary translations

-not require specifically-configured guest OS

-remove the performance hit incurred by using hardware assisted technologies with some hardware support for memory mapping and device and I/O virtualization is out

What are the examples of client based virtualization software in windows

-VMware player/workstation/server

-Microsoft VirtualPC

-Bochs

-VirtualBox

What are the examples of client based virtualization software in macintosh

-Parrallels

-VMware Fusion

What are the examples of client based virtualization software in linux

-OpenVZ

-VirtualBox

-Bochs

KVM (kernel virtual mode)

-Nutanix

What are the examples of hypervisor virtualization software

-VMware vSphere

-Microsoft HyperV

-Xen

-Microsoft Azure

-Nutanix CE

What is VMware vSphere

represents an entire suite of productes

what is Microsoft HyperV

windows clients

what is Xen

-amazon/rackspace/etc.

-cloud backend

what is Microsoft Azure

-multiple clients

-cloud backed

What is Nutanix CE

used in this class