Virtualization refers to creating virtual versions of hardware and resources rather than actual physical versions. There are several types of virtualization including server, storage, desktop, application, and network virtualization. Server virtualization partitions physical servers into smaller virtual servers to maximize resource use. There are two main approaches to full virtualization: software-assisted which uses binary translation, and hardware-assisted which uses virtualization technology in Intel/AMD CPUs. Paravirtualization modifies guest operating systems to communicate directly with the hypervisor rather than simulating hardware. Hybrid virtualization uses paravirtualization for drivers and full virtualization for other features.

2. o refers to the act of creating a virtual (rather than actual) version of something, including
virtual computer hardware platforms, storage devices, and computer network resources.
o Virtualization began in the 1960s
o Type of virtualization
o Server Virtualization
o Storage Virtualization
o Desktop Virtualization
o Application Virtualization
o Network Virtualization

3. Physical server
Operating system
application
Drawback
Cost
Maintenance
OS Doesn't Match With Application
Compatibility

4. Physical server
Operating system
application
Virtual machine monitor or hypervisor
Operating system
application
Operating system
application
VM VM VM

5. Fidelity The environment it creates for the VM is essentially identical to the
original (hardware) physical machine.
Isolation or Safety The VMM must have complete control of the system
resources.
Performance There should be little or no difference in performance between
the VM and a physical equivalent.

6. • Layer that exits between the operating system and hardware
• Provides the necessary services
• Provide features for the smooth running of multiple operating systems.
Physical server
Virtual machine monitor or hypervisor
VM VM VM

7. Server virtualization is the partitioning of a physical server into
smaller virtual servers to help maximize your server resources.
Para Virtualization
Full Virtualization
•Hardware Assisted
•Software Assisted
Hybrid Virtualization: ( Hardware Virtualized with PV Drivers )
OS level Virtualization:

8.  Virtual machine simulates hardware to allow an
unmodified guest OS to be run in isolation
 There is two type of Full virtualizations in the
enterprise market:
 Software assisted full virtualization
 Hardware-assisted full virtualization

9.  t completely relies on binary translation
to trap and virtualize the execution of
sensitive
 It emulates the hardware using the
software instruction sets
 it often criticized for performance issue.

10.  eliminates the binary translation
and it directly interrupts with
hardware using the
virtualization technology
 hardware using the
virtualization technology (Intel
VT-x and AMD-V)

11. Full Virtualization. A full virtualization solution is one that creates virtual and isolated
versions of an entire computer, including CPU, memory, and I/O devices. The key
characteristic of a full virtualization solution is that it allows you to run arbitrary guest
operating systems. This is because the virtual machine looks and feels exactly like a real
computer, up to the point where a guest operating system cannot tell the difference. Full
virtualization should be contrasted with other solutions like paravirtualization, where the
guest OS is specifically modified to run on a hypervisor, and OS-level virtualization, where
groups of processes are isolated from the rest of the system using OS-level features.
Software-only. A software-only virtualization solution is one that does not need special
hardware support, specifically the Intel "VT-x" or "AMD-V" features.
Binary translation. Binary translation is one specific approach to implementing full
virtualization that does not require hardware virtualization features. It involves examining
the executable code of the virtual guest for "unsafe" instructions, translating these into
"safe" equivalents, and then executing the translated code. Alternatives to binary
translation are binary patching, and full system emulation.
Direct execution. This is a mode that can be combined with binary translation. With direct
execution, most code is executed directly on the CPU, and only the code that needs to be
translated is actually translated.

12.  Executable code from the guest is allowed to execute directly on
the host CPU by the hypervisor
 Hypervisor has configured the CPU in such a way that all
potentially unsafe instructions will caused a "trap“
 An unsafe instruction is one that for example tries to access or
modify the memory of another guest
 A trap is an exceptional condition that transfers control back to the
hypervisor
 Once the hypervisor has received a trap, it will inspect the
offending instruction, emulate it in a safe way, and continue
execution after the instruction
 The approach usually has good performance, because the majority
of the instructions will not cause a trap, and will execute straight
on the CPU with no overhead.

13.  It doesn’t need to simulate the hardware for the
virtual machines.
 The hypervisor is installed on a physical server (host)
 guest OS is installed into the environment
 Virtual guests aware that it has been virtualized
 guest source codes will be modified with sensitive
information
 guests will directly communicate with the host
(hypervisor) using the drivers.

14.  combination of both Full & Paravirtualization
 virtual machine uses paravirtualization for specific hardware drivers
 host uses full virtualization for other features.

15.  Operating system-level virtualization is widely used
 also knowns “containerization”
 host uses full virtualization for other features.