Virtualization
- 1. Guided By : Dr. Sudhanshu Kumar Jha (NIT Jamshedpur)
Virtualization
Details, Working, Architecture and Future
By Kumar Harsha(NIT Jamshedpur)
- 2. What is Virtualization
Virtualization is a framework or methodology of dividing the resources of a computer into
multiple execution environments,
Done by applying one or more concepts or technologies such as:
hardware and software partitioning,
time-sharing,
partial or complete machine simulation,
emulation,
quality of service,
and many others.
“Virtualization is an abstraction layer that decouples the physical hardware from the
operating system to deliver greater IT resource utilization and flexibility.” –
www.vmware.com
- 3. Virtualization History
Not a new concept
1960’s at IBM:
M44/44X Project, the goal of which was being to evaluate the then
emerging time sharing system concepts
The architecture was based on virtual machines: the main machine was
an IBM 7044 (M44) and each virtual machine was an experimental image
of the main machine (44X)
IBM and MIT headed research through the years and eventually
developed the idea of a Virtual Machine Monitor (VMM)
- 4. Types Of Virtualization
Virtualization is the creation of a virtual (rather than actual) version of something, such
as an operating system, a server, a storage device or network resources.
In 2005, virtualization software was adopted faster than anyone imagined, including the
experts. There are three areas of IT where virtualization is making headroads, network
virtualization, storage virtualization and server virtualization:
Virtualization
Types
Hardware
virtualization
Desktop
virtualization
High Level
Language
Machine
Virtualization
- 5. Hardware Virtualization
Hardware virtualization or platform virtualization refers to the
creation of a virtual machine that acts like a real computer with
an operating system.
In Hardware Virtualization:
Software executed on these virtual machines is separated from the
underlying hardware resources.
In hardware virtualization, the host machine is the actual machine on
which the virtualization takes place, and the guest machine is the virtual
machine.
- 6. Desktop Virtualization
Desktop virtualization is the concept of
separating the logical desktop from the
physical machine.
In Desktop Virtualization:
The host computer in this scenario becomes a
server computer capable of hosting multiple
virtual machines at the same time for multiple
users.
Thin clients, which are seen in desktop
virtualization, are simple and/or cheap computers
that are primarily designed to connect to the
network.
- 7. High Level Language Machine Virtualization
The virtualization layer sits as an
application program on top of the
operating system
Can run any programs written for
that virtual machine abstraction
regardless of the operating system
hosting that virtual machine
Anyone have an example of this –
Java , Smalltalk, etc.
- 9. Virtualization Architecture
Parent Partition Child Partitions
hypervisor
User Mode
Kernel Mode
Virtualization
Service
Providers
(VSPs)
WMI Provider
Server Core
Kernel
IHV
Drivers
Virtualization
Service
Clients
(VSCs)
Kernel
VMBus Enlightenments
Virtualization Stack
VM Worker
VM Processes
Service
Applications
Provided by:
Host OS
OS
Virtualization
ISV
OEM
Physical Architecture / Hardware
- 10. Hypervisor
A hypervisor, also called a virtual machine manager, is a program
that allows multiple operating systems to share a single
hardware processor.
Classification:
Type 1 (or native, bare metal) hypervisors run directly on the host's
hardware to control the hardware and to manage guest operating
systems.
Type 2 (or hosted) hypervisors run within a conventional operating-system
environment. With the hypervisor layer as a distinct second
software level.
- 11. Type I Hypervisor
Type 1 hypervisors run directly on the
system hardware. They are often referred
to as a "native" or "bare metal" or
"embedded" hypervisors in vendor
literature.
- 12. Limitations of Type I Hypervisor
Old Type I Hypervisors had static allocation of resources which in which if
one of the guest OS requires all the resources (like RAM) of the Host server
then no additional guest OS can be installed on that Host server. Although,
this was overcome by the introduction of the new version of the Type I
Hypervisors that have dynamic or over-allocation that makes the Guest OS
think as if it has all the resources it needs (not more than the what the Host
OS has).
Costly, as the Type I Hypervisor comes for free along with the management
console but for the advance features that actually make a company more
efficient like automated Guest OS migration, automatic switching on/off of
the linked servers in the network etc the cost is a lot more.
- 13. Type II Hypervisor
Type 2 hypervisors run on a host
operating system. When the
virtualization movement first began
to take off, Type 2 hypervisors were
most popular.
- 14. Hypervisor
While using Networking applications on both the Guest as well as Host OS,
sometimes the network traffic can’t pass through due to conflict, e.g. in
Microsoft Outlook.
Licensing can sometimes be on per processor or per core basis which can
turn out to be too costly for even a single hardware server if it has multiple
processor slots.
In File transfer across the Guest OS and Host OS, the File System must be
the same or else it can cause issues.
Guest OS add-ons (appliances) need to be installed for it to run without any
issues.