3.1 IaaS Definition
IaaS: Infrastructure as a Service
Through the internet, provide IT server, storage,
computing power and other infrastructure capacity to the end users and the service fee based on the usage amount of resources.
End user use Web browser to access the service provided from specific IaaS provider.
IaaS’ Features--1
Lower threshold for the use
Users can spent lower cost to rent and get available computing resources. They do not need to purchase a large number of hardware.
The better scalability
Users could dynamically increase or decrease the computing resources on-demand.
IaaS’ Features--2
Easier to manage
Management of resources through the Internet.
More flexible
Through Internet, users can unrestricted control the server in the cloud.
Resources more flexible
Under the conditions of the user to pay, user can always enable or disable all of the resources.
Key Implementation
Technologies of IaaS
Server Virtualization
Storage Virtualization
Networking Virtualization
Cloud Computing Management Platform
3.2 Key Implementation
Technologies of IaaS --1：Server
Virtualization
Technical Terms
CPU Virtualization
Storage Virtualization
I/O Virtualization
Technical Terms
Virtual Machine(虛擬機器)
A virtual server which generate from the server virtualization technology is called a virtual
machine(VM).
Guest OS(客體作業系統)
Run on a virtual machine's operating system is called the guest operating system.
VMM or Hypervisor(虛擬機器管理器)
The software responsible for the management of virtual machine called Virtual Machine Manager(VMM) or
3.2.1 Server Virtualization
Hosted Architecture (寄生架構)
Bare-metal Architecture (原生架構)
Hosted Architecture
Virtual server hosted on the host OS.
VMM is installed on a computer's main OS, and then create and manage virtual machines on the VMM.
Because the VMM and the VM both are parasitic on the main OS, it is known as a parasitic architecture.
Typical examples : Oracle Virtual Box、VMware Workstation.
Parasitic Architecture
Hardware Resource
Drivers
Bare-metal Architecture
The VMM installed directly on a physical
server then produce VM through the
VMM, then install other OS (such as
Window, Linux, etc.) on it.
Typical examples: Vmware ESX、Xen、KVM etc.
Nowadays, widely recognized that the
performance of Bare-metal VM
architecture is better than the parasitic
one.
Hosted Architecture Examples: XEN
Hardware resource
Bare-metal
Architecture
Examples:
VMware
vSphere
3.2.2 CPU Virtualization
Simulating a physical CPU into multiple
virtual CPU for the use of VM. VMM
responsible for virtual CPU time slice
allocating and managing.
CPU Virtualization
The X86CPU instructions set has o-3(4)
privilege level(rating)，level 0 is highest
privilege, it is use to execute OS, and level
3 is lowest privilege, use to execute
applications.
When in the virtualization model, VMM must use the highest privilege level (level 0), while the OS on VM will be diverted to the other on the lower privilege level, it is why we have to process the VM OS-related instructions.
CPU Virtualization
CPU virtualization simulation execution
Through VMM to simulate, such as earlier Vmware.
OS assisted CPU virtualization
Using Hypercall communicate with VMＭ, such as Windows.
Hardware assisted CPU virtualization
Nowadays, hardware-assisted virtualization of CPU is the mainstream technology of VMM, such as Hyper-V, Vmware, etc..
3.2.3 Storage Virtualization
As seen through the VMM, VM memory
has mapping into physical memory. There
are 3 kinds of memory addresses:
The machine address: hardware address of the real machine.
Virtual machine physical address: pseudo-physical address of VM on VMM abstraction.
Virtual address: the address provide by guest OS for application.
3.2.4 I/O Virtualization
Through intercepted guest os on the I / O
device access requests, using software to
simulate real hardware, reuse limited
external devices.
Typical I/O Device
Full virtualization
Para-virtualization
Software simulation
Direct division
Full Virtualization
VMM simulate network cards, disk drives
and other key I / O to form a set of
uniform virtual I / O devices. Where the
Guest OS access to the virtual I/O device,
it will be cached by VMM and then
mapped to actual I / O devices.
Advantages: better performance.
Disadvantages: complexity VMM design
Para-Virtualization
Also known as the front-end / back-end
simulation
On the Guest OS, it need to install special
I / O Driver called the front end driver.
VMM provides a simplified driver that
know as the back-end (Back end driver)
Advantages: Simplified VMM design.
Disadvantages: It need install special I/O drivers on guest OS or modify guest OS.
Software simulation
Using software simulation approach to
realize virtual I / O.
I/O on guest OS cached by VMM, and
transfer to host OS, then through system
call to simulate device action.
Advantages: it could reuse current drivers.
Disadvantages: lower performance, because finish an operation involving multiple registers, there's a context switch times.
Direct Division
The actual I/O devices are assigned to
specific virtual I/O, and guest OS directly
access I/O devices without through VMM
or privilege domain.
Advantages: directly access I/O to reduce consumer of virtualization.
Disadvantage: it need to purchase more hardware devices.
Related technologies: Intel VT-d、AMD
IOMMU、PCI-SIG IOV etc.
3.3 Key Implementation
Technologies of IaaS—2: Storage
Virtualization
Storage Device(HD etc.)
DB FS
File Record Layer
Storage
area Block Cluster
Network Machine
Applications
Devices
3.3 Storage Virtualization--1
Storage Layer Virtualization
Physical device on bottom layer: hard disk drivers is the most important storage
device.
Virtualization mainly in data block storage location
(address) virtualization.
The another important feature of virtual disk is to ensure zero defect of storage, when there is damage to the storage blocks, disk firmware will appreciate mapping it to spare sectors.
Storage Devices
3.3 Storage Virtualization2
Block Cluster Layer Storage Virtualization
Aggregating physical
storages to form an enough capacity with reliable and high performance virtual storage, then divide it into several disks for users.
Divided into in-frequency and out-frequency
virtualization technologies.
Example such as Database as a Service; DAS、Storage Area Network; SAN
Block cluster layer storage
Storage Virtualization
File record layer storage virtualization
Objective: to make it easier for users to use the lower- level storage resources. 。
The main technologies: the file system and database system virtualization.
Application instance:
Network Attached Storage;
NAS
File record layer
3.3 Storage Virtualization--3
3.4 Key Implementation Technologies of
IaaS—3: Network Virtualization
Purpose: integration of multiple hardware
and software with related network into a
resources which can unified control with a
software.
The key technology divided into two
categories: VPN(Virtual Private Network),
VLAN( Virtual Local Area Network).
The technology of virtual network and virtual bridge.
Problems need to solve of
virtual network
How to realize virtual network on physical
machine?
How to dynamic adjust external network to fit
the changing requirement of virtual network?
How to ensure the safety of a virtual network
environment?
How to unified management internal and
external virtual network on physical machines?
Network virtualization technology 1:
Traditional network virtualization
technology
VPN(Virtual Private Network)
For the bottom layer computer, VPN data is same as other network data.
The most common application is, VPN means to create a virtual encrypted on a two or three-tier network .
VLAN(Virtual LAN)
Making a group of hosts on a fixed physical network can be dynamically controllable formation of one or more virtual LAN
Network virtualization technology 2:
Host network virtualization technology
Connect to internet
Connect to server
in intranet Intranet switch Internet switch
host1 host2
Key Implementation
Technologies of IaaS--3
3.5 Cloud Computing
Management Platform
Virtualization Infrastructure resource pool
Resource management platform Business service management platform
Cloud Computing
Management Platform
Business service management platform
To package of resources into a variety of services to provide users with easy-to-use way of external
applications.
Resource management platform
Responsible for the physical device and virtualization resources in a unified management and scheduling
Key technologies include: automated deployment of virtual machines, the ability to provide flexibility, resources status monitoring, measurement, and
Cloud Services Billing
Consumer spending amount = Price x Quantity
For example: EC2 pricing:
Regular Linux 0.031$/hr
Regular Windows 0.08$/hr
Service name Measure index Scale
EC2 Instance Time usage hours
Elastic IP address Quantity of IP address using Frequency
Amazon Cloud Watch Time usage hours
Elastic block store Storage usage * Time Gbytes per month
Elastic load balance Time usage hours
IaaS Providers
NDS
http://nds.ps158.com/
Amazon
http://aws.amazon.com/ec2/
https://cloud.google.com/products/compute-engine/
FETnet(遠傳)
http://www.fetnet.net/cs/Satellite/EBU/CloudIaaS_Intro
Taiwan Mobile(台灣大)
http://www.twmsolution.com/product/IaaS/index_1.htm
Amazon EC2(Elastic Computing
Cloud) Operation Demo
Introduction
Amazon is a largest B2C e-commerce company in America.
To make numerous Server during the low season can be fully applied, so using virtual technology transfer multi- entity Server into Virtual Server and online transactions in the form of rent, forming AWS (Amazon Web Service).
Through the evolution, Amazon not only provide
computing services, storage services, network services, monitoring services, they also provide human services.
