Virtualization & Cloud Flashcards
What is a hypervisor?
Software used to manage and allocate hardware resources to each VM
What is a type 1 hypervisor?
A hypervisor that runs directly on top of the hardware. AKA bare-metal hypervisor
E.G. VMware ESXi, Proxmox
What is a type 2 hypervisor?
A hypervisor that runs as a program on an operating system like a regular computer program. AKA hosted hypervisor
E.G. VMware workstation, Oracle VirtualBox
Type 2 Hypervisor: The OS running directly on the hardware is called the _____ and the OS running in a VM is called the ______
Host OS, Guest OS
What are the primary reasons for using virtualization?
- Partitioning: Divide system resources and run multiple OS on one machine
- Isolation: Provide fault and security isolation at the hardware level
- Encapsulation: Save entire state of a virtual machine to files, move and copy VMs easily
- Hardware independence: Provision or migrate any VM to any physical server
VMs are connected to each other and the external network via:
Virtual switch. Can use VLANs and trunks just like regular L2 switches.
How do virtual switches connect to the physical network?
A trunk to the machine’s NICs
For redundancy, how can we form a port channel between that goes to two separate physical switches?
VPC, virtual port channel
Describe Colocation:
Data centers rent out space for customers to place infrastructure. Datacenters provide space, electricity, cooling, and physical security. Equipment is still the responsibility of the owner but they are not on-prem
Define cloud computing:
A model for enabling on demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction.
What are the 5 essential characteristics of the cloud?
- On-demand self-service
- Broad network access
- Resource pooling
- Rapid elasticity
- Measured service
Describe cloud “on-demand self-service”
Customer is able to start/stop/modify the service freely without direct communication with the service provider
Describe cloud “broad network access”
Service is available through standard network connections and can be accessed through many kinds of devices
Describe cloud “resource pooling”
A pool of resources is provided by the service provides, and when a customer requests a service, the resources to fulfill that request are allocated from the shared pool
Describe cloud “rapid elasticity”
Customers can quickly expand the services they use in the cloud from a pool of resources that appears to be infinite. Likewise, services can be quickly reduced when not needed
Define cloud “measured service”
Cloud service providers measures the customer’s usage of cloud resources, and the customer can measure their own use as well. Customers are charged based on usage
What are the three service models of the cloud?
- Software as a Service
- Platform as a Service
- Infrastructure as a Service