Virtualization & Cloud Computing
- Virtualization Basics
- Don’t confuse virtualization with emulation!
- Emulation uses software to imitate hardware.
- Virtualization uses a system’s actual hardware!
- Recognize the benefits of virtualization.
- There are two types of hypervisors:
- Type 1 (bare metal)
- Type 2 (hosted)
- Virtualization doesn’t pretend to be anything that it’s not! (Remember, virtualization uses a system’s actual hardware!)
- Virtualization saves power; & it consolidates hardware; & it makes system recovery easy, & it’s handy for IT research!
- Hypervisor–V.M.M. (Virtual Machine Monitory)
- the thing that manages & runs the Virtual Machine for us!
- Type 2 Hypervisor–runs on top of the host OS.
- Type 1 Hypervisor–runs directly on top of hardware, independent of the host OS.
- Type 1 boots up the system.
- For a V.M., you will configure the amount of storage, memory, & CPU cores, but the power supply does NOT get virtualized!
- Cloud Ownership
- Private clouds allow access to member only.
- Public clouds are available to anyone.
- A private cloud with contracted management is considered a hybrid cloud.
- Four clouds to remember: public, private, community, & hybrid!
- Cloud Implementation
- V.P.C. (Virtual Private Cloud) depends on the services requested, including IAAS (Infrastructure as a Service), and Paas (Platform as a Service).
- VPC services are very flexible, expandable, and can provide many types of services.
- Building web servers on cloud applications is very easy, but there can be costs associated with the service.
- A VPC is “just my private cloud of machines that are just for me”. We can glue on a public IP address, we can expose certain machines to the Internet if we want.
- Your First Virtual Machine
- Virtual machines need an operating system. (A newly created virtual machine still requires an OS!)
- Snapshots store the current state of a virtual system.
- Most virtual hardware can be changed.
- Most hypervisors can read an ISO image or optical disc.
- Snapshots are like backups for the virtual operating system.
- Hypervisor is the virtual machine host.
- Also, downloaded, pre-made virtual machines are common. (A pre-made virtual machine set up to be firewalls.)
- NAS & SAN
- NAS–Network Attached Storage–file based sharing protocol; NAS is file level!
- SAN–Storage Area Networking (typically more expensive than NAS); SAN is block level!
- NAS runs over a standard network & shows up as normal shares on network.
- HBA (Hose bus adaptor)
- SANs will either use Fibre Channel or iSCSI
- Because it is a block-level storage system, SANs present block devices such as raw drives, not simple file folders like SAMBA shares.
- Platform as a Service (PaaS)
- PaaS enables access to a software development platform without the need to personally host it. Provides an environment for individuals & collaborators to develop and test code & applications.
- Heroku is a great example of PaaS.
- A PaaS allows very quick access to software running live on the Internet.
- Software as a Service (SaaS)
- SaaS enables access to applications via subscription (does away with optical media).
- Microsoft Office 365 is a great example of SaaS.
- Other SaaS examples include Dropbox and Google Docs.
- Dropbox should be considered SaaS for security concerns.
- Infrastructure as a Service (IaaS)
- IaaS enables quick configuration of network resources hosted by someone else.
- Amazon Web Services (AWS) is a great example of IaaS.
- AWS, like most IaaS providers, only charges for the time a server is actually running.
- IaaS provides virtualized hardware such as web servers, load balancers, switches, routers, & back-end processors to create a robust & scalable infrastructure that can be quickly upgraded or downgraded to accommodate changing loads.
