Virtualization Concepts
Virtualization Concepts
Virtualization Concepts
Virtualization Concepts
Virtualization
“Virtualization is the process of presenting
computing resources in ways that users and
applications can easily get value out of them,
rather than presenting them in a way dictated by
their implementation, geographic location, or
their implementation, geographic location, or
physical packaging. In other words, it provides a
logical rather than physical view of data,
computing power, storage capacity, and other
resources.”
Jonathan Eunice, Illuminata Inc
Virtualization
“Virtualization is the process of presenting
computing resources in ways that users and
applications can easily get value out of them,
rather than presenting them in a way dictated by
their implementation, geographic location, or
their implementation, geographic location, or
physical packaging. In other words, it provides a
logical rather than physical view of data,
computing power, storage capacity, and other
Jonathan Eunice, Illuminata Inc
Objectives
After completing this topic, you should be able to:
● Describe what is virtualization
● Know the advantages of Virtualization
● Describe the different types of Virtualization
Objectives
After completing this topic, you should be able to:
Describe what is virtualization
Know the advantages of Virtualization
Describe the different types of Virtualization
What is virtualization
•
The creation of many virtual resources from one
physical resource.
•
The creation of one virtual resource from one or
•
The creation of one virtual resource from one or
more physical resource.
What is virtualization
The creation of many virtual resources from one
The creation of one virtual resource from one or
The creation of one virtual resource from one or
more physical resource.
Virtualization in the News
Microsoft acquired Connectix Corporation, a provider of virtualization software for Windows and Mac based
computing, in early 2003.
Late 2003, EMC announced its plans to acquire VMware for $635 million.
for $635 million.
VERITAS announced that it was acquiring an application virtualization company called Ejascent for $59 million.
Sun and Hewlett-Packard have been working hard in recent times to improve their virtualization technologies.
Virtualization in the News
Microsoft acquired Connectix Corporation, a provider of virtualization software for Windows and Mac based
Late 2003, EMC announced its plans to acquire VMware VERITAS announced that it was acquiring an application virtualization company called Ejascent for $59 million.
Packard have been working hard in recent times to improve their virtualization technologies.
Advantages of Virtualization
Consolidation to reduce hardware cost.
Optimization of workloads.
Increased IT flexibility and responsiveness.
Create an on demand, secure, and flexible
Create an on demand, secure, and flexible
infrastructure.
Virtual machines can be used to provide
secure, isolated sandboxes for running
untrusted applications. E.g. JVM
Advantages of Virtualization
Consolidation to reduce hardware cost.
Optimization of workloads.
Increased IT flexibility and responsiveness.
Create an on demand, secure, and flexible
Create an on demand, secure, and flexible
Virtual machines can be used to provide
secure, isolated sandboxes for running
untrusted applications. E.g. JVM
Types of Virtualization
• Server Virtualization
• Desktop / Application Virtualization
• Network Virtualization
• Storage Virtualization
• Storage Virtualization
Types of Virtualization
Desktop / Application Virtualization
Network Virtualization
Server Virtualization
• A thin low level software layer call
“Hypervisor”
– Intercepts OS calls to hardware
– Provides virtualized CPU and memory for – Provides virtualized CPU and memory for
guests
Server Virtualization
A thin low level software layer call
Intercepts OS calls to hardware
Provides virtualized CPU and memory for Provides virtualized CPU and memory for
Hypervisor
• 2 types of Hypervisors:
– Type 1
• Bare metal / Native
• Runs directly on the hardware with guest OS running on top of them
running on top of them
• E.g. LPAR
– Type 2
• Runs on top of existing OS with guest OS running as third level above the hardware
• E.g. VMware Workstation
Hypervisor
2 types of Hypervisors:
Bare metal / Native
Runs directly on the hardware with guest OS running on top of them
running on top of them
Runs on top of existing OS with guest OS running as third level above the hardware
E.g. VMware Workstation
Advantages of Server Virtualization
• Increased Hardware Utilization
• Security
– Clean images can be used to restore compromised systems.
– Virtual machines can also provide sandboxing – Virtual machines can also provide sandboxing
• Development
– Debugging and performance monitoring
scenarios easily setup in a repeatable fashion.
– Developers have easy access to OS they might not be able to install on their desktops.
Advantages of Server Virtualization
Increased Hardware Utilization
Clean images can be used to restore compromised systems.
Virtual machines can also provide sandboxing Virtual machines can also provide sandboxing
Debugging and performance monitoring
scenarios easily setup in a repeatable fashion.
Developers have easy access to OS they might not be able to install on their desktops.
Disadvantages of Server Virtualization
• Security
– More entry points such as the hypervisor and virtual networking layer to monitor.
• Administration
• Administration
– There are more machines in aggregate.
• Licensing/Cost Accounting
• Performance
– Virtualization effectively partitions resources such as RAM and CPU on a physical machine.
Disadvantages of Server Virtualization
More entry points such as the hypervisor and virtual networking layer to monitor.
There are more machines in aggregate.
Licensing/Cost Accounting
Virtualization effectively partitions resources such as RAM and CPU on a physical machine.
Application Virtualization
• Not installed in the traditional sense
– BUT executed traditionally
• Application publishing
– E.g. Citrix Presentation Server – E.g. Citrix Presentation Server
• API virtualization/emulation
– Virtualize only portion of software
– E.g. WINE (Linux), WABI (SUN), Crossover (OsX)
Application Virtualization
Not installed in the traditional sense
BUT executed traditionally
Application publishing
E.g. Citrix Presentation Server E.g. Citrix Presentation Server
API virtualization/emulation
Virtualize only portion of software
E.g. WINE (Linux), WABI (SUN), Crossover
Advantages of Application Virtualization
• Security
– Virtual applications run in user mode isolating them from OS level functions.
• Management
– Centrally managed software patches
• Legacy Support
– Legacy applications can be run on modern operating systems
• Access
– Virtual applications can be installed on demand to provide failover and replication.
Advantages of Application Virtualization
Virtual applications run in user mode isolating them from OS level functions.
Centrally managed software patches
Legacy applications can be run on modern
Virtual applications can be installed on demand to provide failover and replication.
Disadvantages of Application Virtualization
• Packaging
– Applications must first be packaged before they can be used.
• Resources
• Resources
– Virtual applications may require more resources in terms of storage and CPU.
• Compatibility
– Not all applications can be virtualized easily.
Disadvantages of Application Virtualization
Applications must first be packaged before they
Virtual applications may require more resources in terms of storage and CPU.
Not all applications can be virtualized easily.
Desktop Virtualization
• Able to host and
centrally manage
desktop virtual
machines in the data
center
center
• Able to give end users a
full PC desktop
experience.
• E.g. Vmware, Virtual
PC, Virtual Box
Desktop Virtualization
Able to give end users a
Advantages of Desktop Virtualization
• High Availability
– Downtime can be minimized with replication and fault tolerant hosted configurations.
• Extended Refresh Cycles
– Extend lifespan of client PC.
• Multiple Desktops
– Users can access multiple desktops suited for various tasks from the same client PC.
Advantages of Desktop Virtualization
Downtime can be minimized with replication and fault tolerant hosted configurations.
Extended Refresh Cycles
Extend lifespan of client PC.
Users can access multiple desktops suited for various tasks from the same client PC.
Disadvantages of Desktop Virtualization
• Licensing/Cost Accounting
• Performance
– Virtualization effectively partitions resources – Virtualization effectively partitions resources
such as RAM and CPU on a physical machine.
Disadvantages of Desktop Virtualization
Licensing/Cost Accounting
Virtualization effectively partitions resources Virtualization effectively partitions resources such as RAM and CPU on a physical machine.
Network Virtualization
• Virtual LAN (VLAN)
• Virtual Private Networks (VPN)
Network Virtualization
Virtual Private Networks (VPN)
Advantages of Network Virtualization
• Customization of Access
– Administrators can quickly customize access and network options such as bandwidth
throttling and quality of service.
• Consolidation
• Consolidation
– Physical networks can be combined into one virtual network for overall simplification of
management.
Advantages of Network Virtualization
Customization of Access
Administrators can quickly customize access and network options such as bandwidth
throttling and quality of service.
Physical networks can be combined into one virtual network for overall simplification of
Disadvantages of Network Virtualization
• Increased complexity
• Performance overhead
• Need for administrators to have a larger skill
set.
set.
Disadvantages of Network Virtualization
Performance overhead
Need for administrators to have a larger skill
Storage Virtualization
• RAID
– process of abstracting logical storage from physical storage
Storage Virtualization
process of abstracting logical storage from
Advantages of Storage Virtualization
• Migration
– Data can be easily migrated between storage locations without interrupting live access to the virtual partitions.
• Utilization
• Utilization
– Utilization of storage devices can be balanced to address over and under utilitization.
• Management
– Many hosts can leverage storage on one centrally managed physical device.
Advantages of Storage Virtualization
Data can be easily migrated between storage locations without interrupting live access to the
Utilization of storage devices can be balanced to address over and under utilitization.
Many hosts can leverage storage on one centrally managed physical device.
Disadvantages of Storage Virtualization
• Lack of Standards and Interoperability
– Storage virtualization is a concept and not a standard.
• Metadata
• Metadata
– There is a mapping between logical and
physical location, the storage metadata and its management becomes key to a working reliable system.
Disadvantages of Storage Virtualization
Lack of Standards and Interoperability
Storage virtualization is a concept and not a
There is a mapping between logical and
physical location, the storage metadata and its management becomes key to a working reliable
Which virtualization are we learning?
IBM Virtualization:
– HMC
• Hardware Management Console
– LPAR – LPAR
• Logical Partition
• Allows running multiple, independent
• Operating system images of AIX and Linux on a single server
Which virtualization are we learning?
Hardware Management Console
Allows running multiple, independent
Operating system images of AIX and Linux on a
Web links
– www.kernelthread.com/publications/virtualizatio n/
– www.infoq.com/articles/virtualization
Web links
www.kernelthread.com/publications/virtualizatio
www.infoq.com/articles/virtualization-intro
