211 Midterm Prep

Question 1

What Is Virtualization?

Lecture 1

Answer 1

Virtualization is the process of creating a software based / virtual version of an operating system that is visible via a Hypervisor.

Virtualization allows for the creation of Virtual Machines

Question 2

Name and Describe some of the reasons why virtualization is used today.

Lecture 1

Answer 2

1. Server Consolidation - Instead of having a ton of physical servers, you can replace them with a few larger servers.
2. Isolation - Guest Operating Systems are fully isolated from the host running them. This protects the host from any software issues that may occur on the VM
3. Disaster Recovery. Virtual Machines allow for snapshots, which makes backups and disaster recovery easier.
4. Dynamic Load Balancing - Live Migration provides easy load-balancing across infrastructure by allowing users to move VMs from busy hosts to new or unused hosts on demand.

Question 3

Describe some of the benefits of virtualization.

Lecture 1

Answer 3

• Allows a high level of mobility. All virtualized OS environments can be moved between physical hosts freely.
• Great for getting the most out of your resources.
• Scalable
• Use less data, space, and cost less than having multiple physical machines
• Consolidation and Centralization of Resouces (No idea what this one means if somebody wants to clarify)
• Isolation
• Better disaster recovery / availability
• Speed of service and automation
• Compatable with public cloud services

Question 4

What are the 3 different approaches to Virtualizaion?

Lecture 1

Answer 4

1.Software Virtualization - Enables a single computer server to work with multiple virtual systems
2.Hardware Assisted Software Virtualization - Uses the physical hardware of the host system to support the virtual machine management software.
3.Para-Virtualization - Virtualization that presents a software interface to the virtual machines which is similar to the hardware / software interface.

Question 5

What is the main role of a Hypervisor?

Lecture 1

Answer 5

Hypervisors enable us to be able to perform virtualization. Hypervisor software runs on the host and translates the VM onto the hardware of the host PC.

Question 6

What are the 2 types of Hypervisors?

Lecture 1

Answer 6

Type 1: Also known as bare metal, these are installed directly on the physical server (Hyper-V, VMware)

Type 2: Also known as Hosted, have a layer of host operating systems between the physical device and the hypervisor itself. (VirtualBox, VMware, Oracle)

Question 7

What are the 2 architectures of Type 1 Hypervisors?

Lecture 2

Answer 7

Monolithic and Micro-Kernelized

Question 8

What are the attributes of Monolithic Hypervisors?

Lecture 2

Answer 8

1. Drivers exist within the hypervisor
2. Superior performance
3. Shares drivers with the host PC, which limits hardware support for the VMs
4. The list of compatable hardware is very short
5. Contain more security and stability issues

Question 9

What are the attributes of Micro-Kernelized Hypervisors?

Lecture 2

Answer 9

1. Used by Hyper-V
2. Mainly governed by a Server Management / Parent Partition
3. Can run numerous drivers created by multiple vendors which removes the need for hardware-linked drivers.
4. More Secure and Stable than Monolithic Hypervisors.

Question 10

Hypervisor Design Principals (taken from the lecture slides)

Lecture 2

Answer 10

Question 11

What is the role of VMMS (Virtual Machine Management Systems)

Lecture 2

Answer 11

VMMS manages the state of VMs and launches VM’s work processes for each child partition.

Question 12

Describe the VMBus and its roles

Lecture 2

Answer 12

VMBus is a tool within Hyper-V that enables logical communication between partitions.

The VMBus redirects request to virtual devices, allowing files to be draged and dropped between VM and host.

VMBus runs in kernel mode and is resonsible for enabling communication between the Virtual Service Providers that allows support for memory hardware.

Question 13

How does Hyper-V support Isolation?

Lecture 2

Answer 13

Hyper-V supports isolation through partitions.

Partitions are logical units of isolation, supported by Hyper-V. For hypervisors to work through Microsoft, at least one root partiton must be running Windows.

Question 14

Describe some of the benefits of running a virtualized environment.

Lecture 2

Answer 14

• Virtalized Environments allow multiple different OS instances to execute at the same time on a single physical system
• Drive resources available on a physical host are used for multiple VMs, which act as stand alone systems completely isolated form the Host.
• Allows for the usage of Emulated and Synthetic hardware devices

Question 15

Describe Emulated hardware components

Lecture 2

Answer 15

Emulated hardware devices exist as physical hardware.

They use built in drivers to operate through virtualization, however they have more overhead due to emulation because they were not designed specifically to be used on virtual machines.

Question 16

Describe Synthetic Hardware Components.

Lecture 2

Answer 16

Synthetic devices are high performance, software based devices that control access to physical hardware.

Designed specifically for virtualized environments, and run in kernel mode so they do not have additonal overhead to worry about.

Question 17

Describe Synthetic Hardware Components.

Lecture 2

Answer 17

Synthetic devices are high performance, software based devices that control access to physical hardware.

Designed specifically for virtualized environments, and run in kernel mode so they do not have additonal overhead to worry about.

Question 18

What are Generation 1 VMs?

Lecture 2

Answer 18

Generation 1 VMs require that hardware natively support the virtual hardware being used on the machine.

Used specifically for older versions of Operating Systems.

While they support the usage of both emulated and synthetic hardware, they must be booted from an emulated IDE.

Question 19

What are Generation 2 VMs?

Lecture 2

Answer 19

Generation 2 are the newest model of Hyper-V Virtual Machines.

Uses newer operating systems that are natively enlightened to virtualization. No emulated devices are required.

Does not use older BIOs technology, and instead uses Unified Extensible Firmare Interface (UEFI) and secure boot to operate.

Question 20

Why might a fixed VHD be used in a production environment over a dynamic VHD?

Quiz 1

Answer 20

If you have limited underlying phsyical storage, you are better able to allocate the storage you have.

With Dynamic VHDs, you may end up unexpectedly running out of storage becuase you don’t have a defined or fixed amount of space set for each VHD.

Question 21

What does the use of NUMA ensure?

Quiz 1

Answer 21

NUMA ensures that in multi-processor systems, any given processor wil use the memory that is directly attached to it.

Question 22

What file extention is used for Hyper-V Virtual Disks?

Quiz 1

Answer 22

.vhdx

Question 23

What are containers?

Oct 6 Lecture

Answer 23

A container is a staudard unit of software that packages up code and dependencies so that an application runs quickly and reliably in different computer environments.

Question 24

Why are containers referred to as “lightweight”?

Oct 6 Lecture / Kahoot 2

Answer 24

Containers are referred to as “lightweight” because thye share the machines OS kernel.

They are also smaller and require less start up time than a VM.

Question 25

What are docker container images? | Oct 6 Lecture

Answer 25

A docker container image is a lightweight, standalone software executable package that includes everything needed to run a single application. This includes code, runtime, system tools, system libraries, and settings.

Question 26

What is containerization? | Oct 6 Lecture

Answer 26

Contanerization is the packaging of software code to allow for the creation of a container that runs consistently on any infrastructure.

Question 27

What are some benefits of containerization? | Oct 6 Lecture

Answer 27

Containerizaition allows developers to create and deploy applications quickly and securely. Containerization also allows applications to be written once, and run on any infrastructure.

Question 28

Compare and contrast VMs and Containers. | Oct 6 Lecture

Answer 28

VMS: * Each application runs in its own virtual machine and its associated overhead * Applications are completely isolated from other applications * REsources available can be controlled through configuration of VM resources * Virtualization eliminates the need for an entire physical device for one application, but still requires an operating system Containers: * Each application is isolated at a user-mode level, and runs its own application * Diferent conainerized applications can be dependent on the same containers or different containers (what the hell does this MEAAAAANNN) * Containerization eliminates the need for an entire operating system for each application

Question 29

What are the 3 steps when working with containerization? | Oct 6 Lecture / Kahoot 2

Answer 29

- Composition file (or manifest) – that specifies the images used and any actions required e.g., In Docker, it is called Docker file - Container Image e.g., docker image - Containers – contains all runtimes and binary ## Footnote I dont know how these are "steps", however this is in her notes and this is the answer to the question if it appears on the test.

Question 30

List some of the benefits of containerization | Oct 6 Lecture

Answer 30

* Resources - Containers have less overhead due to not having to run a complete virtualized desktop and operating system to function * Speed - Due to having less overhead, the deployment and operation speed for containers is generally faster than virtual machines. * Isolation - Complete isolation from other containers on a system allows for more fault tolerance as well as security.

Question 31

Differentiate between Windows containers, and Hyper-V containers | Oct 6 Lecture

Answer 31

Windows containers run isolated application containers inside of the host OS kernel. They are all still communicating with the host operating system directly, and are slightly less isolated. Isolation is provided through namespaces and process isolation. Hyper-V containers isolate eachother through a lightweight VM which takes longer to deply and has more overhead, but provides an added level of isolation and security from the host operating system.

Question 32

What are container runtimes? | Oct 13th Lecture

Answer 32

Container runtimes (container engines) are a software component that runs containers on a host operating system provided by Windows Server. Container runtimes provide the ability to communicate over a network through virtual switches, as well as providing tools to help develop and manage new containers.

Question 33

What is a docker? | Oct 13th Lecture

Answer 33

Docker is an open-source attempt to automate the dpeloyment of software apps inside of containers. Dockers provide an additional layer of abstraction and automation of OS-Level virtualization on linux. Docker allws developers to easily deploy applications inside of a sandbox environment to run on the host Linux system.

Question 34

What is the benefit of using a docker? | Oct 13th Lecture

Answer 34

Less overhead than VMs Allows users to package an application with all dependencies into a standardized unit for software development.

Question 35

What are the components that run on top of a Docker Engine? | Oct 13th Lecture

Answer 35

Docker Client - Performs actions against the Docker Engine (are the enemies?) Docker Powershell - Executes against the REST API provided by the Docker Engine Docker Compose - Enables the definition and running of multi container dockers

Question 36

What is a Docker Client REST API? | Oct 13th Lecture

Answer 36

A REST API (Application Programming Interface) is a set of rules to define how applications or devices can connect to and communicate with eachother on a network.

Question 37

Describe the development workflow when using Docker | Oct 13th Lecture

Answer 37

1. Dockerize an appilcation (add the docker file to the application folder) 2. Start the container using an image file, and create the isolated environment 3. Push the image to a docker registry or hub 4. On any machine you would like to run the application, install the image file from the hub.

Question 38

What is Podman? | O?ct 17th Lecture

Answer 38

Podman is a new container engine used for managing containers, images, volumes, and pods. Provides extra features to help developers in Kubernetes environments.

Question 39

What is a pod? | Oct 17th Lecture

Answer 39

Pods are temporary groupings of one or more containers that is the SMALLEST possible unit of computing resources that a container orchestration platform can manage. Podman groups containers in a single namespace, network, and security context.

Question 40

What is Kubernetes? | Oct 17th Lecture

Answer 40

Kubernetes is a container orchestration platform. Can coordinate containers running on different VMs or even different physical machines. Can work with any container that meets the OCI Image specification.

Question 41

Compare and Contrast Docker and Podman. | Oct 17th Lecture

Answer 41

* Docker is an all in one platform that provides tools for specific tasks * Docker has no native concept of pods * Docker needs to continuously running background daemon programs to create images and run containers * Podman collaborates with other projects for specific purposes, and doesn't natively have all needed tools included * Podman launches containers and pods whne needed as a seperate child processes | Podman and docker are compatable with eachother.

Question 42

How does Podman provide elevated levels of security? | Oct 17th Lecture

Answer 42

Docker relys on a daemon that runs on the root device, opening up a potential attack surface. Podman allows you to run a rootless container, which provides an added level of isolation.

Question 43

Define Container Networking | Oct 18th Lecture

Answer 43

Container networking is the act of enabling containers to communicate with other containers and the host. This allows containers to share resources, data, and other applications.

Question 44

What are teh 2 options available when running an application in a container in terms of networking? | Oct 18th Lecture

Answer 44

1. The application runs in the host network namespace - this is the most common configuration 2. Applications run in their own network namespace - other programs running on different devices need to be able to connect to this program. This is ued when there are many containers interracting, and each container needs their own IP assignment.

Question 45

What are the 4 types of container networking? | Oct 18th Lecture

Answer 45

1. None - No networking is applied to the container, providing full isolation. This should only be used in test environments before the container is deployed on a network 2. Bridge - Allows connection to other interfaces ofthe host machine and other containers on the same host. 3. Overlay - Containers act like they are all on one machine even if they are not. This allows multiple computers to communicate on the same network subnet 4. Underlay - Used to connect host interfaces directly to containers running on the host computer.

Question 46

What are 5 emerging trends in container technology? | Oct 18th Lecture

Answer 46

1. FlexVolume - A new container storage interface that enaables third party venders to add support for their Kubernetes storage backends 2. Runtime Security - Provides isolation and security for containers 3. Helm - Simplifies building complex applicationsd with Kubernetes and allows for full control of application configuration 4. Ksonnet - Simplifies the deployment and management of Kubernetes clusters 5. Serverless computing - No description for this so yolo

Question 47

Describe the functions of: * RD connection Brokers * RD Gateways * RDP * RD Web Access | Quiz

Answer 47

RD Connection Brokers distribute users to specific virtual sessions or desktops RD Gateways provide external connectivity from outside the network to the VDI services RDP is the access protocol that defines communication with virtual desktop Operating Systems RD Web Access provies a portal over HTTPS for authentication to the VDI service.

Question 48

What memory management technique takes unused memory from virtual machines and allocates it based on the needs of other VMs? | Quiz

Answer 48

Ballooning

Question 49

What is the correct term for the virtualization layer that is inserted into the boot process of the host machine that controls access to physical hardware? | Quiz

Answer 49

The hypervisor

Question 50

What is used to determine the importance of a VM getting shares of the CPU in terms of resource contention? | Quiz

Answer 50

Relative Weight

Question 51

When ballooning, what is responsible for inflating and deflating the "balloon"? | Quiz

Answer 51

The VM Manager

Question 52

Describe the function of: * Storage Virtualization * Storage Virtualization software * Storage Controllers | Quiz

Answer 52

Storage Virtualization is the pooling of physical storage from multiple network storage devices into a single storage device Storage Virtualization Software is used to create virtual storage partitions based on physical hardware Storage controllers are used to manage the combined space from different phyiscal storage devices connected on a network.

Question 53

Compare and contrast Thick and Thin provisioning. | Quiz

Answer 53

Think provisioning is a type of storage pre-allocation. The complete ammount of VHD storage capacitiy is pre-allocated on the physical storage during the creation of a virtual disk. This consumes all the space allocated to it in the datastore from the start, so the space can't be used by other VMs. Thin provisioning consumes only the space it needs, and eventually grows over time.

Question 54

Describe the benefits of virtual networking | Sept 29th Lecture

Answer 54

*Less Expensive * Easier to implement / less complex * More secure * More scaliable

Question 55

What are the 5 tenets of virtualization benefits? ## Footnote This is Ryan's personal guide to anything in 211 that has to do with benefits. This is NOT part of any official documentation from OC / Adebola / the textbook.

Answer 55

1. Faster Operating Speeds 2. Easier Management 3. Lower Cost 4. Isolation from other devices 5. More secure | If your answer includes any of these 5 you will get at least 3/5 correct

Question 56

Compare and contrast the 3 types of virtual switches. | Sept 29th Lecture

Answer 56

If you can't do this yet I am sorry for your loss. The only thing different on this test is there is no default switch listed. Only External, Internal, and Private.

Question 57

Name the different types of VLANs | Sept 29th Lecture

Answer 57

1. Management VLAN - separate VLAN set up for management traffic. 2. Data VLAN - It is designed only for user-generated data. 3. Voice VLAN - help separate the LANs for VoIP. 4. Default VLAN: can be of two types * all the ports on the device is belong to one user * all the ports are assigned even when the switch is not in use 5. Native VLAN: untagged traffic accept when it is received on the trunk port

Question 58

Describe the 3 modes of Private VLANs | Sept 29th Lecture

Answer 58

Isolated Mode - Primary PVLAN mode, complete isolation from other hosts. No direct communication is possible Community Mode - Allows multiple hosts in the same community to communicate. Requires a second VLAN ID Promiscuous mode - Can communicate with hosts in either isolated or community mode. Useful for servers seperated by all hosts.