Lecture 11 12

VIRTUALIZATION & CLOUD COMPUTING

Lecture # 11-12

CSE 423

Working with Desktop Virtualization

• Desktops have been the bane of the administrator’s existence ever since they first appeared on the market.

• If desktops are not locked down, there can be no control and there always are a lot of issues.

• Another major problem of distributed PCs is the amount of applications to manage and deploy to them.

• Using a system stack simplifies the way you construct PCs as well as the way you manage applications because it structures how computer systems are built from the ground up.

Point of Access for Secure Service (PASS) system construction model

• This system stack is based on the construction of a computer system that responds to corporate needs in three ways

• PASS system “kernel” is designed to meet the needs of the average or generic user. It contains all of the software components required to perform basic office automation and collaboration tasks.

• Role-based applications and commercial software are added on top of the kernel to meet the requirements of the special IT roles every person plays within the organization.

• ad hoc layer responds to highly specialized IT requirements that are often expressed on an individual basis.

The Anatomy of a Desktop

DESKTOP core components• The core OS layer, which includes the OS itself and any patches it requires.

• The application layer, which is designed to provide added functionality to the end user.

• The user data layer, which contains all of the user’s data including user produced documents, presentations, and more

These are the three key components of a desktop, and if you can abstract these layers from one another, you can significantly reduce desktop management overhead. This is where desktop virtualization products can help

Move To Desktop Virtualization

• More and more organizations are turning to a virtual desktop to simplify the desktop management model. There are several reasons why desktop virtualization often makes more sense than managing physical desktops.

• First, you can provide centrally managed desktops to users on any endpoint device

• Second, you can lock down virtual desktops because they are controlled centrally and, therefore, are easier to provision

• You spend less time on endpoints—the actual physical PCs

• You can provide service level agreements (SLAs) only for the central desktop and not for the endpoint itself

Move To Desktop Virtualization

• You can create locked and encrypted virtual desktop images that can be time controlled to meet timely requirements

• Information can be secured by keeping the virtual desktop inside the datacenter

• Complex or sensitive applications can be encapsulated and isolated into specific PC VMs to ensure proper operation

Available Desktop Virtualization Products

• There are several different types of desktop virtualization engines. They usually fit within two different virtualization models: local versus centralized

• The local desktop virtualization model, often called Client-side Desktop Virtualization, focuses on using the endpoint’s own resources for running the virtual desktop.

– Virtualization software is installed on the physical desktop, and a corporate virtual desktop image is provided to the end user. The end user then runs the virtual desktop on top of their physical desktop.

• Centralized • and is often called Server-hosted Desktop Virtualization.

• Here, the virtual desktop will run on top of a production hypervisor and will be accessed remotely by the end user. All the end user requires is any device that supports a remote desktop connection.

• The virtual desktops run on top of host servers using shared storage to ensure desktop availability.

• Local model supports both managed and unmanaged product usage

Virtual Desktop Licensing

• When working with virtual desktops you must always consider licensing• If you’re working with Windows, you will get a break from Microsoft because

Microsoft has released the Windows Vista Enterprise Centralized Desktop (VECD) license with following feature:

• Unlimited installs of Windows Vista Enterprise on a server.• Virtual desktops are licensed by access device, whatever the device.• Each user can have up to four virtual instances running on the access device at

one time.• Organizations can run either static or dynamically hosted desktop architectures.

• Virtual desktops can run on Microsoft or non-Microsoft infrastructures.

Potential Desktop Virtualization Scenarios

• locked and encrypted desktop virtual machines.– Machines are centrally prepared and then encrypted to protect their

content. They are distributed to end users on portable devices, such as USB memory sticks, DVDs, external USB disk drives, or other removable storage devices.

– Because they are encrypted, they are completely protected from tampering. The user must provide the appropriate unlocking key to launch the VM.

• Unmanaged desktop virtualization stems from the use of tools such as Vmware Workstation or Microsoft Virtual PC.

• Both tools are installed locally on the user’s desktop and rely on the desktop’s processing capabilities to run VMs.

• In unmanaged mode, the user installs their own version of the virtualization software and creates and runs his or her own virtual machines

• Unmanaged desktop virtualization can lead to issues within the organization

• Stateful virtual desktops, focuses on centrally managed desktops that are tied to each specific user.

• In this model, each user connects to his or her own particular desktop virtual machine(s).

• The VMs are stored in a central shared storage container, much as they are when you virtualize server software. Host servers running production hypervisors manage all of the desktop virtual machines and make sure they are highly available.

• require a significant amount of storage.

• Stateless virtual desktops• Generation of virtual machines on an as-needed basis.• The advantage of this model is that the machines are completely volatile

and built on the fly.

Identify Desktop Virtualization Audiences

• The basic productivity worker will require fewer application types. Primarily text based and log in at distributed time.

• The knowledge worker will require a more powerful centralized desktop because they tend to run multiple business and productivity applications at the same time. Include application richer in graphics and tend to log in at same time.

• The rich desktop user will most likely run multiple computer- and graphics intensive applications at the same time. Ex: Engineers or traders

Centralized Desktop Virtualization Infrastructures• Persistent or assigned desktops

– The desktop is tied to one single user and the same desktop is provided to the user each time he or she logs on.

– Use when : Few user, storage not concern

• Non-persistent, volatile, or pooled desktops– A new, generic desktop is provided to the user each time he or she logs on

to the infrastructure.– Applications and user profile data are provided at logon to customize the

shared image to meet this user’s particular requirements.

• Persistent clone desktop– A personalizable clone is generated the first time a user logs on; from that

point on, the user relies on that clone each time he or she logs back on