VIRTUAL SERVERS

• Although Cisco is more known for their networking DEVICES (ROUTERS, SWITCHES, FIREWALLS), they also offer HARDWARE SERVERS such as UCS (Unified Computing System)
• The largest vendors of HARDWARE SERVERS include Dell, EMC, HPE, and IBM

SERVERS BEFORE VIRTUALIZATION

• Before VIRTUALIZATION, there was a one-to-one relationship between a PHYSICAL SERVER and OPERATION SYSTEM
• In that OPERATING SYSTEM, apps providing SERVICES (such as a WEB SERVER, EMAIL SERVER, etc) would run
• One PHYSICAL SERVER would be used for the WEB SERVER, one for the EMAIL SERVER, one for the DATABASE SERVER, etc.
• This is inefficient for multiple reasons:
  • Each PHYSICAL SERVER is expensive and takes up space, power, etc.
  • The RESOURCES on each PHYSICAL SERVER (CPU, RAM, STORAGE, NIC) are typically under-utilized

VIRTUALIZATION (TYPE 1 HYPERVISOR)

• VIRTUALIZATION allows us to break the one-to-one relationships of HARDWARE to OS, allowing multiple OS’s to run on a single PHYSICAL SERVER
• Each INSTANCE is called a VM (Virtual Machine)
• A HYPERVISOR is used to manage and allocate the HARDWARE RESOURCES (CPU, RAM, etc.) to each VM
• Another name for a HYPERVISOR is VMM (Virtual Machine Monitor)
• The type of HYPERVISOR which runs directly on top of hardware is called a TYPE 1 HYPERVISOR
  • Examples include : VMware ESXi, Microsoft Hyper-V, etc.
• TYPE 1 HYPERVISORS are also called bare-metal hypervisors because they run directly on the hardware (metal).
  • Another term is native hypervisor
• This is the type of HYPERVISOR used in data center environments

VIRTUALIZATION (TYPE 2 HYPERVISOR)

• TYPE 2 HYPERVISORS run as a program on an OS like a regular computer program
  • Examples: VMware Workstation, Oracle Virtualbox, etc
• The OS running directly on the hardware is called the HOST OS
• The OS running in a VM is called a GUEST OS
• Another name for a TYPE 2 HYPERVISOR is hosted hypervisor
• Although TYPE 2 HYPERVISORS are rarely used in data center environments, they are common on personal-use devices (for example, if a MAC/Linux user needs to run an app that is only supported on Windows, or vice-versa)

WHY VIRTUALIZATION?

• PARTITIONING :

  • Run multiple OS’s on ONE PHYSICAL MACHINE
  • Divide system resources between VIRTUAL MACHINES

• ISOLATION :

  • Provide FAULT and SECURITY ISOLATION at the hardware level
  • Preserve performance with advanced resource controls

• ENCAPSULATION :

  • Save the entire state of a virtual machine to files
  • Move and copy virtual machines as easily as moving and copying files

• HARDWARE INDEPENDENCE :

  • Provision or migrate any virtual machine to any physical server

VIRTUAL NETWORKS

• VMs are connected to each other and the EXTERNAL NETWORK via a VIRTUAL SWITCH running on the HYPERVISOR
• Just like a regular PHYSICAL SWITCH, the vSWITCH’s INTERFACES can operate as ACCESS PORTS or TRUNK PORTS and use VLANs to separate the VMs at LAYER 2
• INTERFACES on the vSWITCH connect to the PHYSICAL NIC (or NICs) of the SERVER to communicate with the EXTERNAL NETWORK

INTRO TO CLOUD COMPUTING

• Traditional IT infrastructure deployments were some combination of the following:

  • ON-PREMISES

    • All SERVERS, NETWORK DEVICES, and other infrastructure are located on company property
    • All equipment is purchased and owned by the company using it
    • The company is responsible for the necessary space, power, and cooling

  • CO-LOCATION

    • Data centers that rent out space for customers to put their infrastructure (SERVERS, NETWORK DEVICES)
    • The data center provides the space, electricity, and cooling
    • The SERVERS, NETWORK DEVICES, etc are still the responsibility of the end customer, although they are not located on the customer’s premises
• CLOUD SERVICE provide an alternative that is hugely popular and is continuing to grow
  • Most people associate “CLOUD” with PUBLIC CLOUD PROVIDERS such as AWS
    • Although this is the most common USE of CLOUD SERVICES, it’s not the only one

CLOUD SERVICES

• The American NIST (National Institute of Standards and Technology) defined cloud computing in SP (Special Publication) 800-145

• To understand what the CLOUD is, let’s look at the following outlined in SP 800-145:
  • FIVE ESSENTIAL CHARACTERISTICS
  • THREE SERVICE MODELS
  • FOUR DEPLOYMENT MODELS

THE FIVE ESSENTIAL CHARACTERISTICS OF CLOUD

• ON-DEMAND SELF-SERVICE

  • The CUSTOMER is able to use the SERVICE (or stop the SERVICE) freely (via a web portal) without direct communication to the SERVICE PROVIDER

• BROAD NETWORK ACCESS

  • The SERVICE is available through standard NETWORK connections (ie: the Internet or PRIVATE WAN) and can be access through many kinds of DEVICES

• RESOURCE POOLING

  • A POOL of RESOURCES is provided by the SERVICE PROVIDER and when a CUSTOMER requests a SERVICE (for example creates a new VM), the RESOURCES to fulfill that request are allocated from the shared POOL

• RAPID ELASTICITY

  • CUSTOMERS can quickly expand the SERVICE they use in the CLOUD (for example: add new VMs, expand STORAGE, etc) from a POOL of RESOURCES that appear to be infinite. Likewise, they can quickly reduce their SERVICES when not needed

• MEASURED SERVICE

  • The CLOUD SERVICE PROVIDER measures the CUSTOMER’s usage of CLOUD RESOURCES and the CUSTOMER can measure their own use as well. CUSTOMERS are charged based on usage (for example: X Dollars per Gigabyte of STORAGE per day)

THE THREE SERVICE MODELS OF THE CLOUD

• In CLOUD COMPUTING, everything is provided on a “SERVICE” model

• For example: rather than the END USER buying a PHYSICAL SERVER, mounting it on a rack, installing the hypervisor, creating the VM, etc. the SERVICE PROVIDER offers all of this as a SERVICE

• There are a variety of SERVICES referred to as “___________ as a SERVICE” or “__aaS”

• The THREE SERVICE MODELS of CLOUD COMPUTING are:

  SOFTWARE as a SERVICE (SaaS) - Example : MS Office 365

PLATFORM as a SERVICE (PaaS) - Examples : AWS Lambda and Google App Engine 

INFRASTRUCTURE as a SERVICE (Iaas) - Examples: Amazon EC2 and Google Compute Engine

DEPLOYMENT MODELS

• Most people assume that “CLOUD” means PUBLIC CLOUD PROVIDERS like AWS, AZURE, and GCP

• Although “PUBLIC CLOUD” is the most common deployment model, it’s not the ONLY one

• The FOUR DEPLOYMENT MODELS of CLOUD COMPUTING are:

• PRIVATE CLOUD

• PRIVATE CLOUDS are generally only used by large enterprises

• Although the CLOUD is PRIVATE, it may be owned by a THIRD PARTY

  • For example: AWS provides PRIVATE CLOUD SERVICES for the American DoD

• PRIVATE CLOUDS may be ON or OFF PREMISES

  • Many people assume “CLOUD” and “ON-PREM” are two different things but that is not always the case

• The same kind of SERVICES offered are the same as in PUBLIC CLOUDS (SaaS, PaaS, IaaS) but the infrastructure is reserved for a SINGLE ORGANIZATION

• COMMUNITY CLOUD

• Least common CLOUD deployment

• Similar to PRIVATE CLOUD, but the INFRASTRUCTURE is reserved for use by a SPECIFIC GROUP or ORGANIZATION

• PUBLIC CLOUD

• The most common CLOUD deployment

• Popular PUBLIC CLOUD service providers include:

  • AWS
  • MS AZURE
  • GCP (Google Cloud Platform)
  • OCI (Oracle Cloud Infrastructure)
  • IBM Cloud
  • Alibaba Cloud

• HYBRID CLOUD

- Basically ANY combination of the preview THREE DEPLOYMENT TYPES
- Example: A PRIVATE CLOUD which can offload to a PUBLIC CLOUD when necessary

BENEFITS OF CLOUD COMPUTING

• COST

  • CapEx (Capital Expense) of buying HARDWARE and SOFTWARE, setting up DATA CENTERS, etc. are reduced or eliminated

• GLOBAL SCALE

  • CLOUD SERVICES can scale GLOBALLY at a rapid pace. SERVICES can be set up and offered to CUSTOMERS from a geographic location close to them

• SPEED / AGILITY

  • SERVICES are provide ON DEMAND and vast amounts of RESOURCES can be provisioned within minutes

• PRODUCTIVITY

  • CLOUD SERVICES remove the need for many time-consuming tasks such as procuring physical servers, racking them, cabling, installing and updating equipment, etc.

• RELIABILITY

  • Backups in the CLOUD are very easy to perform. Data can be mirrored at multiple sites in different geographic locations to support disaster recovery

CONNECTION TO PUBLIC CLOUDS