chap 21 Virtualization

A server that runs a virtualization solution. Most of the time it is called the host. Typically it has lots of computational resources like processors, cores and memory in order to run multiple virtual machines.

Also called virtualization host

Hypervisor

A software emulation of a physical computer. It runs an operating system and applications just like a physical computer, but it exists as a file on a hypervisor. Multiple virtual machines can run on a single hypervisor, sharing the host's resources.

Also called guest machine or guest.

virtualization guest

a virtual solution provided by a vendor. Nearly all vendors provide a virtual option when you buy their products.

Virtual Routers like CSR1000v, ASAv (virtual Adaptive Security Appliance) and Firepower Threat Defense Virtual are all Virtual Appliances.

virtual appliance

CSR1000v

a Cisco virtual router that runs IOS-XE software

This is considered a Virtual Appliance.

a virtual version of Cisco’s ASA (Adaptive Security Appliances) firewall

This is considered a Virtual Appliance.

ASAv

virtual version of Cisco’s Firepower firewall solution. This is considered a Virtual Appliance.

Firepower Threat Defense virtual

all virtualization solutions have a virtual switch (Vswitch) that each host uses. the vswitch acts just like a regular switch except it doesn’t run STP.

Vswitches basically allow hosts to assign VLANs to Virtual machines. They can also perform more advanced tricks like trunking and can even support switch features like CDP, LLDP (Link Layer Discovery Protocol) and SPAN and security features like Private VLANs.

Virtual Switch

Vswitches come in 2 forms what are they?

Standard and Distributed

Free version switch that offers basic features. With this variety , every host (hypervisor) will have its own independent Vswitch, meaning if you configure VLAN11 and VLAN12 on host’s vswitch, you’ll need to config the same VLANs on any new host you add into the network that’ll be sharing the workload. You do this just like you would when adding a new switch into the network if you aren’t using VTP

Standard Vswitch

Option of Vswith that creates a single logical virtual switch that runs on all hosts, It supports advanced features and shares configuration between all hosts. A distributed vSwitch is just like a switch stack where all switches share the single configuration.

Distributed Vswitch

A storage solution that allows multiple virtual machines to access the same storage resources simultaneously, typically used in clustered or high-availability environments for data redundancy and efficient resource utilization

the most common shared storage solutions include access a SAN (Storage Area Network) or NAS (Network-attached storage) through iSCSI or Fibre Channel. Doing this permits all hosts in your network to access the same common storage enabling more features

shared storage

each host utilizes its local storage to create a logical SAN (Storage Area Network) across the network, which all the virtual hosts use as virtual machines.

virtual storage

Cisco’s main Hyper Converged solution that runs VMware or Hyper-V with virtual storage on its Cisco Unified Computing System (UCS) server

Cisco Hyperflex

A software-defined storage solution from VMware that is integrated into the hypervisor, creating a shared storage pool from local server disks to provide high performance and simplified management for virtualized environments.

VMware virtual SAN

the Microsoft solution that provides virtual storage.

Microsoft Storage Spaces

A Storage Area Network (SAN) is a dedicated, high-speed network that provides block-level storage to servers. It consolidates storage resources, making them available to multiple servers as if they were directly attached. SANs typically use protocols like Fibre Channel, iSCSI, or Fibre Channel over Ethernet (FCoE) for connectivity.

SAN

______ refers to a software layer that hides the complexities of specific hardware devices from the operating system and other software. This allows for more flexible and portable software development, as applications can interact with hardware through a standard interface rather than having to deal with device-specific details.

Developers don't have to write code specific to each hardware device

Hardware abstraction

a saved state of a virtual machine (VM) at a specific point in time, capturing its data, configuration, and settings.

Essentially, it's like a "point-in-time" copy of the VM, allowing administrators to revert to that specific state if needed. 

Snapshot

allow you to quickly create a copy of a VM, They’re a handy feature for creating several VMs based on a golden image that you’ve already patched and configed exactly the way you want it.

Clones

Virtual Machine Migration

and

Storage Migration

There are 2 types of migrations, what are they?

moving a VM form one host to another

Virtual Machine Migration

moving a VM from one storage location to another. For example, moving a VM from internal storage to an iSCSI datastore.

Storage Migration

A protocol that enables storage devices to be connected over a network using TCP/IP. It essentially allows you to access storage as if it's locally attached, even if the storage device is remote

Internet Small Computer System Interface

iSCSI

bare metal hypervisor-when the entire server and OS is dedicated to virtualization, the hypervisor can directly access all hardware on the system. This is the most common enterprise solution since it provides the most features and has the best solutions.

examples are

VMware ESXi

Hyper-v

Xen

Type 1 (hypervisor)

when the virtualization solution runs on top of your desktop OS as an application and is mostly meant for IT/developer testing since is offers a lot less features and performance.

Also called desktop virtualization.

Examples would be

KVM

VirtualBox

VMware Workstation/Fusion

Type 2 (hypervisor)

when the VM is not aware its a VM. The hypervisor presents hardware to the VM that it can interact with.

Hardware Virtualization Machine

HVM

paravirtualization

a type of virtualization where the guest is enlightened to the fact it is a VM and directly contacts the hypervisor instead of using emulated hardware. It gives better performance but it requires drivers to be installed on the guest OS for it to function.

VMware’s Type 1. fully featured hypervisor, is based on custom Linux OS. Management duties are carried out via ESXi’s web interface or thru VMware management solution VCenter.

ESXi is not free , VMware does provide a free license for standalone hosts to play with.

VMware ESXi

Xen/KVM

These are 2 Opensource Hypervisors that are free but require a strong Linux background.

Microsoft Type 1 hypervisor that we can run as its own OS for a dedicated deployment or we can install it on a Windows Server or Desktop as a role.

Managed with Hyper-V Management Tool.

Hyper-V

VMware Workstation is a paid (Tier 2) Type 2 solution for Windows and Linux, while Fusion s a paid (Tier 2) Type 2 for Mac.

VMware Workstation

VMware Fusion

VirtualBox

Oracles free open source Type 2

A group of interconnected switches operating as a single logical switch, offering increased port density, simplified management, higher bandwidth, and redundancy. Managed as a single unit with one master switch.

This is achieved through a stacking cable or port that allows multiple physical switches to be connected in a ring or star topology. One switch acts as the master (or active) switch, managing the stack and presenting a single management interface. The other switches act as members (or slaves), taking their configuration from the master.

switch stack

The most popular scripting language in the world. It has readable syntax, is easy to use and is very extensible.

Python

JavaScript Object Notation is a data exchange format for most systems that have agreed to use communicating data. Its job is to express data in a structured human-readable way. Data is presented in key/value pairs; information can also be nested as required.

Json structures data into key/value pairs seperated with a colon inside curly braces {}. It also requires the keys and values to …

Use double quotes and not single quotes.

Boolean (true or false) values must be lowercase

Trailing commas must not be used.

JSON

YAML Ain’t Markup Language is a grammatically incorrect data serialization language that is designed to be easy for a human to read and interpret data. It is used by a growing number of tools such as Ansible.

YAML is made up of 3 components and they are

Mapping -simple key-value pairs like Name: Todd

Lists works the same as any plain text bullet list, each item is on its own line and starts with a - (hyphen)

Scalars every string, Boolean, or number is a scalar. This means the key and value in a pair are each a scalar. every item in a list is a scalar. Scalar is a programming term.

Whitespace is important in YAML and TAB is not supported. In YAML there must be a space between the colon in a mapping and the value.

YAML

an application programming interface that follows the principles of Representational State Transfer (REST). It provides a way for different software systems to communicate and exchange information securely over the internet. RESTful APIs use standard HTTP methods (like GET, POST, PUT, DELETE) to interact with resources identified by unique URLs. 

API Application Programmable Interface

RESTful API

RESTful API commands/actions

POST = create

GET = Read

PUT = update/replace

PATCH = update/modify

DELETE = delete

RESTful API commands

POST

GET

PUT

PATCH

DELETE

HTTP STATUS CODES Meaning

200 OK

201 Created

400 Bad Request

401 Unauthorized

403 Forbidden (don’t have permission)

404 Not Found

500 Internal Server error (Server issue)

503 Service unavailable (Server unable to complete request)

HTTP STATUS CODES

200

201

400

401

403

404

500

503

404

Which HTTP status code would you expect if the resources wasn’t found?

VMware Workstations is a Type 2 hypervisor.

VMware Workstations is what type of hypervisor?

Use double quotes and NOT single quotes.

Boolean values must be lowercase.

Trailing commas are not allowed.

What are the JSON syntax rules?

E Hyper-V

What is the virtualization products made by Microsoft?

A ESXi

B Workstation

C Xen

D KVM

E Hyper-V

Representational state transfer

What does REST stand for?

A) The specific path to the resource you’re trying access through the API.

API resources, a.k.a. Resource Indicators , indicate the target services or resources to be requested, usually, a URI format variable representing the resource's identity.

Which of the following best describes a Resource in Restful API?

A The specific path to the resource you’re trying access through the API.

B The security token for the request

C Filtering option for the request

D the full URL

B virtual appliance

A Cisco CSR1000v virtual router is which type of virtual resource?

A virtual machine

B virtual appliance

C virtual network

D virtual storage

E Type-1

B No

YAML does not support TAB characters.

Does YAML support TAB characters?

A Yes

B No

B Simple key-value pairs

ex

Name: Todd

What does a mapping refer to in YAML?

A Simple value-key pairs

B Simple key-value pairs

C Complex value-key pairs

D Complex key-value pairs

GET

Which HTTP operation in RESTful API is most like a show command in Cisco IOS?

A POST

You use POST operation to “post” info to Restful API. It is the most like a config command.

Which HTTP Operation in RESTful API most closely resemble a configuration command in Cisco IOS?

A POST

B DELETE

C GET

D PATCH

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