Virtualisaton 3.2 Flashcards
Advantages of client virtualisation
The machines can be standardised and used across a large variety of different hardware configurations.
Easier to backup, secure, encrypt and repair disk images as it can be done centrally via the server.
Easier to configure, deploy and management can be done centrally via the server.
More reliable and long lasting
Minimal maintenance and therefore lower costs.
Disadvantages of client virtualisation
Availability and performance depend on network/internet connection.
The network infrastructure needs to handle all that extra bandwidth.
Increased server load can cause poor performance
Cost (of servers) is high
Expertise needed to install the client requires training
Multiple monitor connections may not be possible with some solutions.
What is storage virtualisation?
Used for data management
process of grouping the physical storage from multiple network storage devices so that it looks like a single storage device.
Storage virtualisation advantages
Reduces the amounts of physical storage required
Simplifies and reduces the time required for backup, recovery and general storage activities.
Storage virtualisation disadvantages
Can be difficult to solve problems when something goes wrong
Cloud computing
Cloud Computing - The delivery of shared computing resources, software or data as an on demand service through the internet instead of your computer’s hard drive.
Virtualisation
Virtualisation differs from cloud computing because Virtualisation is software that manipulates hardware, Cloud Computing is a service that results from that manipulation. To put it simply, virtualization is a technology, where cloud is an environment
Advantages of cloud computing
Outsourced IT – provided by a service provider
Quick to setup/Management is easy and quick to change
Pay as you go/Flexible to need (e.g SaaS Software as a service); you pay for what you need e.g stora
Scalability/ Expandable – can scale IT capacity on an “as required” basis
Frees up physical space as less storage servers required
Cost of replacing On Premises Hardware/ maintenance reduced (equipment/ running costs.
Remote access more convenient
Staff and students have access to work
Lower need/cost for Expertise of managing the on premises hardwar
Disadvantages of cloud computing/virtualisation
Security risks - trusting a third party
Bandwidth/Relies on internet issues
No redundancy/ (Redundancy ensures that your business is able to retrieve information
at any given time) so will require the purchase of a redundancy plan if there is a failure in
the technology.
No Control over security
No Control over backing up/Access to own data
Cloud hosting large amounts of data expensive,
Fault with provider - No control over backing up and restoring data, No internet no access Costs (hosting)
What is cloud virtualisation
Cloud Virtualisation is where businesses pay a Cloud service provider such as? to host and run virtualisation technologies for their business. Hybrid Cloud Computing is a mixture of private cloud, public cloud and lo owned services
What is a paravirtualisation?
Paravirtualisation (PV) a guest OS is modified prior to installation inside a virtual machine (VM) to allow for an interface to the virtual machine that can differ from that of the underlying hardware
What is hardware assisted virtualisation
Hardware assisted virtualisation: architectural support facilitating the building of a virtual machine monitor that allows guest OS to run in isolation.
What is hybrid virtualisation
Hybrid Virtualisation is a combination of Paravirtualisation and Hardware assisted Virtualisation
Hybrid Virtualisation where parts of the guest operating system use paravirtualization for certain hardware drivers, and the host uses Hardware virtualization for other features. This often produces superior performance on the guest without the need for the guest to be completely paravirtualized.
Advantages of hybrid virtualisation
improves the reliability of virtual machines
Improves the performance and efficiency
Combines the advantages of Paravirtualisation and Hardware assisted virtualisation
Disadvantages of hybrid virtualisation
Training required to implement and manage the environment
Upfront Costs
