Virtualisation Flashcards
What is it?
process of creating a virtual version of something, such as a server or computer system, using software instead of hardware.
Why are virtual environments easier to maintain?
don’t require software installation and updates on individual computers, saving both time and money
What do all virtualization types share in common?
the end result - virtualized stimulation of a device or resource
How is virtualization accomplished?
- by dividing a single piece of hardware into two or more ‘segments’
- each segment operates as its own independent environment
What’s server virtualization?
- involves hiding the server resources (including number + identity of individual physical servers, processors + OS) from server users.
- intention is to increase resource sharing
server virtualization - why is the OS and hardware closely linked?
so that only some applications can run simultaneously to prevent problems
server virtualization - what’s needed to operate?
additional applications and additional physical servers need to be installed
what does server virtualization enable?
a single physical server to run several applications, each appearing to have its own server
server virtualization - what does the layer of the software enable?
this abstraction is often referred to as the hypervisor.
what is a hypervisor?
- a hardware virtualisation technique that allows multiple guest operating systems (OS) to run on a single system at the same time.
- aka a Virtual Machine Manager (WMM)
what is client/desktop?
- a virtualization technology used to separate a computer desktop environment from the physical computer
what is the ‘virtualized’ desktop stored on?
a centralized or remote server and not the physical machine being virtualized
what does desktop virtualization do?
- ‘virtualizes desktop computer’
- you interact with a virtual desktop in the same way you would use a physical desktop
benefit of desktop virtualization
it lets you remotely log in to access your desktop from any location
what is storage virtualization?
- pulling together physical storage from multiple network storage devices into what appears to be a single storage device that’s managed from a central console
- commonly used in Storage Area Networks (SAN)
what 2 forms can storage virtualization come in?
- block-level - allows a SAN to use numerous storage arrays across the network as if they were a single array
- file-level - allows Network Attached Storage (NAS)
What is cloud computing used to refer?
a situation in which ‘shared computing resources, software, or data are delivered as a service and on-demand through the internet’
How does virtualization differ from cloud computing?
- virtualization is software that manipulates hardware, while cloud computing refers to a service that results from that manipulation.
- based on virtualization, but actually isn’t virtualization
what is a hybrid cloud?
- a cloud computing environment which uses a mix of locally owned services, private cloud + public cloud services
- by allowing workload to move between private and public clouds as computing needs and costs change, hybrid cloud gives businesses greater flexibility and more data deployment options
evaluate the use of virtualization technology
\+ reduced long-term costs \+ increased use of devices \+ simplified disaster recovery - adds complexity - increased impact if system fails - significant up front/placement cost - end users unaware of technology - extra IT skills needed
